Line segment AC has a length of 120 and contains
point B.If AB=5x+20andBC=6x-10, which
equation shows the relationship between the lengths
of line segments AB, BC, and AC?
A)5x+20=120
B)6x-10=120
lest
C)(5x+20)-(6x-10)=120
D)(5x+20)+(6x-10)=120

Answers

Answer 1

An equation that shows the relationship between the lengths of line segments AB, BC, and AC include the following: D. (5x + 20) + (6x - 10) = 120.

How to determine the midpoint of a line segment?

In Mathematics, the midpoint of a line segment with two end points can be calculated by adding each end point on a line segment together and then divide by two (2).

Since B is the midpoint of line segment AC, we can logically deduce the following:

Line segment AB = Line segment BC

Line segment AC = Line segment AB + Line segment BC

By substituting the given line segments into the equation above, we have the following:

120 = (5x + 20) + (6x - 10)

Read more on midpoint here: brainly.com/question/17918978

#SPJ1

Line Segment AC Has A Length Of 120 And Containspoint B.If AB=5x+20andBC=6x-10 Whichequation Shows The

Related Questions

? Question
The cube of m varies inversely as the square root of n.
Which two equations model this relationship?

Answers

The two equations that models the inverse proportion relationship are:

m³ = k/√n

m³√n = k

How to identify Inverse proportions?

Inverse proportion is defined as a type of proportionality relationship. Thus, when two quantities are said to be inversely proportional, then it means that as one quantity increases, the other decreases.

We are told that the cube of m varies inversely as the square root of n. Thus:

m³ ∝ 1/√n

If k is the constant of proportionality , then we say that:

m³ = k/√n

We can also cross multiply to get:

m³√n = k

Read more about Inverse Proportions at: https://brainly.com/question/1266676

#SPJ1

if F(x)=2x^3+2 and G(x)=2x^2-3x-2,what is f(x)-g(x)

Answers

Step-by-step explanation:

F(x)=2x^3+2

G(x)=2x^2-3x-2

Now,

g(x) - f(x)= 2x^2-3x-2 - (2x^3+2)

= 2x^2-3x-2 - 2x^3-2

=2x^2-3x-2-2-2x^3

=2x^2-3x-4-2x^3

: 3

Triangle RST
was dilated with the origin as the center of dilation to create triangle R'S'T'
. The triangle was dilated using a scale factor of 34
.

The lengths of the sides of triangle RST
are given.

Enter the lengths of the sides of triangle R'S'T'
below.
(Decimal values may be used.)

Answers

The lengths of the sides of triangle R'S'T'

R' = (-3.75, 2.25), S' = (2.25, 3) and T' = (2.25, -4.5).

We have the coordinates of triangle RST are given as

R (-5, 3), S(3, 4) and T(3, -6)

and, The scale factor is given as: 3/4

Now, The rule of dilation is

(x, y) = 3/4 (x, y)

Then, we can write

R' = (-5 x 3/4, 3 x 3/4)

R' = (-3.75, 2.25)

S' = (3 x 3/4, 4 x 3/4)

S' = (2.25, 3)

and, T' = (3x 3/4, -6x 3/4)

T' = (2.25, -4.5)

Learn more about dilation here:

brainly.com/question/8532602

#SPJ1

Please help me guys!

Answers

Answer:

B

Step-by-step explanation:

Please say thank you

1
A farmer wants to grow cabbage and wheat in his field. He divides the field into two sections as shown below.
200 yd
In how much area of the field will the farmer grow whear?
OA 41,000 square yards
OB. 20,000 square yards
OC. 42,000 square yards
OD. 21,000 square yards
Reset
210 yd
Submit

Answers

21,000 yd² of the field will the farmer grow wheat.

We have,

Length of yard = 210 yd

width of yard = 200 yd

As per the figure the yard is cut in diagonal form in which half portion have wheat and half potion have Cabbage.

So, the resulting shape of field in which what will grow is right angles triangle

= 1/2 x base x height

= 1/2 x 200 x 210

= 100 x 210

= 21,000 yd²

Thus, 21,000 yd² of the field will the farmer grow wheat.

Learn more about Area of Triangle Here:

https://brainly.com/question/27683633

#SPJ1

Please help I’ll mark you as brainliest if correct

Answers

Answer: Trapezoid, Square, Rhombus, Parallelogram

Step-by-step explanation:

Calculator A circle has a radius of 4 ft. What is the area of the sector formed by a central angle measuring 260°? Use 3.14 for pi. Enter your answer, rounded to the nearest tenth in the box. ft² 3 4 5 6​

Answers

The area of the sector is 36.6 ft².

We have,

To calculate the area of the sector, we need to find the fraction of the entire circle it represents and then multiply it by the area of the entire circle.

The central angle of 260° represents (260/360) or 13/18 of the entire circle.

The area of the entire circle with a radius of 4 ft can be calculated using the formula:

A = πr², where π is approximately 3.14.

Substituting the values,

The area of the entire circle is A = 3.14 x (4 ft)² = 3.14 x 16 ft² = 50.24 ft².

To find the area of the sector, we multiply the area of the entire circle by the fraction represented by the central angle:

Area of sector = (13/18) x 50.24 ft² = 36.64 ft².

Rounded to the nearest tenth

Thus,

The area of the sector is 36.6 ft².

Learn more about Circle here:

https://brainly.com/question/11833983

#SPJ1

Does anyone know this answer??

Answers

Approximately 99.7% of scores lie in the shaded region.

We have,

The empirical rule, also known as the 68-95-99.7 rule, provides an estimate of the percentage of scores that lie within a certain number of standard deviations from the mean in a normal distribution.

According to this rule:

Approximately 68% of scores lie within 1 standard deviation of the mean.

Approximately 95% of scores lie within 2 standard deviations of the mean.

Approximately 99.7% of scores lie within 3 standard deviations of the mean.

Now,

In the given scenario, the shaded region represents the area between -2 and 3 standard deviations from the mean on the x-axis.

This encompasses the area within 3 standard deviations of the mean.

And,

Since 99.7% of scores lie within 3 standard deviations of the mean, we can estimate that approximately 99.7% of scores lie in the shaded region.

Therefore,

Approximately 99.7% of scores lie in the shaded region.

Learn more about normal distribution here:

https://brainly.com/question/31327019

#SPJ1

Which is a defining attribute of an isosceles triangle?

Answers

Two sides are congruent to each other. The third side of an isosceles triangle which is unequal to the other two sides is called the base of the isosceles triangle. The two angles opposite to the equal sides are congruent to each other.

How to explain the triangle

In an isosceles triangle, two sides have the same length, making them congruent. These two sides are often referred to as the "legs" of the triangle.

The angles opposite the congruent sides in an isosceles triangle are also congruent. These angles are typically referred to as the "base angles."

The remaining side, called the "base," is not congruent to the legs of the triangle. The base is usually the side that connects the two base angles.

Leans more about triangles on

https://brainly.com/question/17335144

#SPJ1

The width of a rectangle measures ( 2.4x + 3.5 ) centimeters, and its length measures ( 1.2x + 6.8 ) centimeters. Which expression represents the perimeter, in centimeters, of the rectangle?

Answers

The perimeter of the rectangle can be shown by Option C.

Perimeter of a rectangle

The perimeter of a rectangle is the total distance around its outer boundary. To calculate the perimeter of a rectangle, you need to know the lengths of its two adjacent sides, typically referred to as length (l) and width (w).

We know that the perimeter can be given by;

P = 2(l + b)

P = 2[(2.4x + 3.5) + (1.2x + 6.8)]

P = 2[2.4x + 3.5 + 1.2x + 6.8]

P = 2[2.4x +  1.2x + 3.5 + 6.8]

P = 2[3.6x + 10.3]

P = 7.2x + 20.6

Learn more about rectangle:https://brainly.com/question/15019502

#SPJ1

12. a) In a quiz contest, the quiz master announced the following rules. (+10) marks is awarded for each correct answers. (-5) marks is given as penalty to each incorrect answers. 0 mark is given for not supplying any answers. (i) If the group-A, answered 6 questions correctly and 4 question incorrectly, how many marks did the group-A secure? (ii) If the group-B answered 7 questions correctly, 2 questions incorrectly and did not answer for 1 question, how many marks did the group-B secure? (iii) Which group secured more marks and by how many?​

Answers

Group-B secured more marks than group-A by a margin of 20 marks

Answers to the aforementioned questions

(i) To calculate the marks secured by group-A, we need to multiply the number of correct answers by the marks awarded for a correct answer and subtract the product of the number of incorrect answers and the penalty for each incorrect answer.

Group-A secured:

Marks = (Number of correct answers * Marks for correct answer) - (Number of incorrect answers * Penalty for incorrect answer)

      = (6 * 10) - (4 * 5)

      = 60 - 20

      = 40 marks

Therefore, group-A secured 40 marks.

(ii) For group-B, we need to consider the number of correct answers, incorrect answers, and unanswered questions to calculate the total marks.

Group-B secured:

Marks = (Number of correct answers * Marks for correct answer) - (Number of incorrect answers * Penalty for incorrect answer) + (Number of unanswered questions * Marks for not supplying answers)

      = (7 * 10) - (2 * 5) + (1 * 0)

      = 70 - 10 + 0

      = 60 marks

Hence, group-B secured 60 marks.

(iii) To determine which group secured more marks and by how many, we compare the marks obtained by group-A and group-B.

Group-A secured 40 marks, while group-B secured 60 marks.

The difference in marks secured by group-B compared to group-A is:

60 - 40 = 20 marks.

Therefore, group-B secured more marks than group-A by a margin of 20 marks.

Learn more about margin at https://brainly.com/question/13248184

#SPJ1

PLEASE HELP 40 PTS!!!
___________________________answer individually
___________________________
2. This scatterplot shows the relationship between a player's level in a game and the point total in the level. Answer the questions about the scatterplot.

a. The best model for these data would be (linear / exponential / quadratic).

b. This table shows the values from the scatterplot. Find the regression equation for the model that you
chose in Part a. Round your answer to the nearest hundredth.

c. using the equation that you found, in part B, predict the point total in the 10th level. Round your answer to the nearest integer

Answers

The solution to the given scatter plot is:

a)  Exponential

b) y = 587.52x

c) 894

How to Interpret the Scatter Plot?

Scatter plots are basically al type of data visualization that shows us the relationships that exists between variables.

a) The best model for the given scatter plot is definitely exponential because of the nature of the points and curve.

b) The regression equation for the model has the general formula:

Y = a + bx

Thus, from the given scatter plot, we can say that the equation is:

y = 587.52x

c) Using the equation that you found, in part B, using an online regression equation calculator, we can say that the prediction of the point total in the 10th level is: 894

Read more about Scatter Plot at: https://brainly.com/question/6592115

#SPJ1

Which expression is equivalent to 1.1 n − 3.8 + 1.9 n + 9.1 ?

Answers

Combine like terms by adding the 1.1n and 1.9n terms:

1.1n + 1.9n = 3n

Combine the constant terms:

-3.8 + 9.1 = 5.3

The expression becomes:

1.1n − 3.8 + 1.9n + 9.1 = 3n + 5.3

Therefore, the expression that is equivalent to 1.1n − 3.8 + 1.9n + 9.1 is 3n + 5.3.

Answer:

3n+5.3

Step-by-step explanation:

(1.1×n+1.9n)+(−3.8+9.1) = 3n+5.3

can the width be zero? explain.

Answers

Answer:

no

Step-by-step explanation:

(I'll assume you're talking about a rectangle)

If the width is zero, the shape would be a line. Therefore, the width cannot be zero.

Feel free to tell me if I did anything wrong! :)

100 Points! Algebra question. Photo attached. Find the exact value of the expression. Please show as much work as possible. Thank you!

Answers

The exact value of the given expression of tan 15 ° can be found to be 1 / √3.

How to find the exact value of tangent ?

When given a tangent degree, you can find the exact value by relating it to the Sine and Cosine values as shown below :

tan ( x ) = sin ( x ) / cos ( x )

Given that x is 15 degrees, we have :

tan ( 15 ) = sin ( 15 ) / cos ( 15 )

The values of sine and cosine :

sin(30) = 1/2

cos(30) = √3/2

This means the relation is:

tan ( 15 ) = sin ( 15 ) / cos ( 15)

= ( 1 / 2 ) / (√3 / 2 )

= 1 / √3

=  0.2679

Find out more on exact value at https://brainly.com/question/31013650

#SPJ1

What statements are true about isosceles triangles?

Answers

Answer: About two angles are congruent

Step-by-step explanation:

At what price did Berkshire Hathaway close on the previous day based on the table?

Answers

The price at which Berkshire Hathaway close on the previous day based on the table is $199,740.

What does closing price of stock means?

The closing price of stock means the final trading price at which a particular stock or security is traded on given trading day. It is the last recorded price of a stock when market closes for the day.

The closing price is an important indicator used in financial markets to evaluate the performance and value of a stock. It serves as a reference point for investors, analysts and traders to assess the overall market sentiment and make investment decisions.

Read more about closing price

brainly.com/question/30155035

#SPJ1

Marissa is painting her rectangular patio, with the exception of a bench that does not need to be painted:

rectangle with a length of x plus 15 and width of x plus 10 with a rectangle in the bottom right corner labeled bench that has a length of 5 and width of 1

Write an equation to determine the area, A, of the patio that will be painted.

A = (x + 20)(x + 11)
A = (x + 15)(x + 10) + 5
A = (x + 15)(x + 10) − 5
A = (x + 9)(x + 10)

Answers

The equation A = (x + 15)(x + 10) − 5 represents the area of the patio that will be painted, where A is the total area.

Option C is the correct answer.

We have,

The equation A = (x + 15)(x + 10) − 5 represents the area of the patio that will be painted.

The dimensions of the rectangular patio are given as (x + 15) for the length and (x + 10) for the width.

These values account for the extra length and width added to the original dimensions (x) to include the bench area.

To determine the total area of the patio that will be painted, we calculate the product of the length and width, which is (x + 15)(x + 10).

However, we need to subtract the area of the bench, which has a length of 5 and a width of 1.

Hence, we subtract 5 from the product to exclude the bench area.

Therefore,

The equation A = (x + 15)(x + 10) − 5 represents the area of the patio that will be painted, where A is the total area.

Learn more about rectangles here:

https://brainly.com/question/15019502

#SPJ1

Answer:

C

Step-by-step explanation:

i took the test :)

have a great day.!

Is EFGH below a rectangle? Explain.
(Picture recorded below)

Choose the correct answer below.
Yes, because EFGH is a parallelogram and its diagonals are congruent.

No, because EFGH is a parallelogram and its diagonals are congruent.

No, because EFGH is a parallelogram but its diagonals are not congruent.

Yes, because EFGH is a parallelogram but its diagonals are not congruent.

No, Because EFGH is not a parallelogram.

Answers

Yes, because EFGH is a parallelogram and its diagonals are congruent.

How to prove the statement

To prove the statement, we have to know the properties of a rectangle.

The properties of a rectangle are listed thus;

A rectangle is a quadrilateralThe opposite sides are parallel and equal to each otherEach interior angle is equal to 90 degreesThe sum of all the interior angles is equal to 360 degreesThe diagonals bisect each otherBoth the diagonals have the same lengthA rectangle with side lengths a and b has the perimeter as 2a+2b units

Learn more about rectangles at: https://brainly.com/question/25292087

#SPJ1

Classify the triangle by its sides and angles. Explain your reasoning.

Answers

The triangle that has been shown is a scalene obtuse triangle.

What is a scalene obtuse angle triangle?

A triangle called a scalene triangle has three sides that are all different lengths. In other words, a scalene triangle has three different angles and no two of its sides have the same length.

A triangle with one obtuse angle is referred to as an obtuse triangle. Any angle that is greater than 90 degrees but less than 180 degrees is referred to as an obtuse angle.

Thus we have a scalene obtuse triangle.

Learn more about triangle:https://brainly.com/question/2773823

#SPJ1

can you find the slope

Answers

The slope of the points in this table is equal to -3.

How to calculate the slope based on the table?

In Mathematics and Geometry, the slope of any straight line can be determined by using this mathematical equation;

Slope (m) = (Change in y-axis, Δy)/(Change in x-axis, Δx)

Slope (m) = (y₂ - y₁)/(x₂ - x₁)

Based on the information provided in the table, we can logically deduce the following data points on the line:

Points on x-axis = (0, 1).Points on y-axis = (7, 4).

By substituting the given points into the slope formula, we have the following;

Slope, m = (4 - 7)/(1 - 0)

Slope, m = -3/1

Slope, m = -3.

Read more on slope here: brainly.com/question/3493733

#SPJ1

What is the sine of Ø?

Answers

The value of sin of θ given in the unit circle using the coordinates is -√13/7.

Given a unit circle.

We know that any point on the unit circle can be represented in terms of the angle that the point makes with the positive X axis as,

x = cos θ and y= sin θ

Here θ is the angle formed by the positive X axis with the point.

Here also given a unit circle.

So using the coordinates, we get

cos (θ) = -6/7

sin (θ) = -√13/7

Hence the value of sin of θ is -√13/7.

Learn more about Unit Circle here :

https://brainly.com/question/30485412

#SPJ1

HELPSSS PLEAS BTW 7TH GRADE MATH

Answers

The surface area for each rectangular prism is given as follows:

3) S = 195.5 mm².

4) S = 158.1 m².

What is the surface area of a rectangular prism?

The surface area of a rectangular prism of height h, width w and length l is given by:

S = 2(hw + lw + lh).

This means that the area of each rectangular face of the prism is calculated, and then the surface area is given by the sum of all these areas.

Hence, for item 3, the surface area is given as follows:

S = 2 x (8.2 x 5 + 8.2 x 4.3 + 5 x 4.3)

S = 195.5 mm².

For item 4, the surface area is given as follows:

S = 2 x (4.1 x 3 + 4.1 x 9.4 + 3 x 9.4)

S = 158.1 m².

More can be learned about the surface area of a rectangular prism at https://brainly.com/question/1310421

#SPJ1

How to use desmos to solve the system

Answers

The graph of the system of equations on the image at the end, there we can see that the solution is (110, 95).

How to solve the system of equations graphically?

Here we want to solve the given system of equations:

2x + 3y = 505

5x + 3y = 835

Using a graphing tool.

To solve the system graphically we just need to graph both equations on the same coordinate axis and find the point where the graphs intercept.

On the image at the end, you can see the graph of the system of equations. On that image we can see that the solution of the system of equations is (110, 95).

Learn more about systems of equations at:

https://brainly.com/question/13729904

#SPJ1

nedd help pls someone​

Answers

The volume of the sphere is 196 cm³

What is volume of sphere?

Volume is defined as the space occupied within the boundaries of an object in three-dimensional space. It is measured in units³

The sphere is a geometrical three-dimensional solid having a curved surface.

The volume of a sphere is expressed as;

V = 4/3 πr³

where r is the radius.

π = 3

r = 7

V = 4/3 × 3 × 7²

V = 4 × 49

V = 196 cm³

Therefore the volume of the sphere is 196 cm³

learn more about volume of sphere from

https://brainly.com/question/10171109

#SPJ1

Help!!!!! I need help

Answers

Answer:

Step-by-step explanation:

Graph a straight line, slanting down, with a y-intercept of 4  (the point (0,4)) and an x-intercept of 8 (the point (8,0)).  Your line should slope down-1-over-2.  Line should be solid and shade everything below the line.

(sorry, Brainly doesn't offer graphing tools, so I had to just describe the line.  Hope this helps you!)

100 Points! Algebra question. Photo attached. Please show as much work as possible. Thank you!

Answers

We have shown that E₀ cos⁴θ = E₀ (1/2 + (cos2θ)/2)².

Let's start by condensing the supplied equation, E₀ cos⁴θ:

E₀ cos⁴θ = E₀ (cos²θ)²

Now, we can rewrite cos²θ in terms of Sin²θ using the identity sin²θ = 1 - cos²θ:

cos²θ = 1 - sin²θ

Reintroducing this into the expression:

E₀ (cos²θ)² = E₀ (1 - sin²θ)²

Expanding the square:

E₀ (1 - sin²θ)² = E₀ (1 - 2sin²θ + sin⁴θ)

Now, let's simplify the expression (1 - 2sin²θ + sin⁴θ):

1 - 2sin²θ + sin⁴θ = (1 - sin²θ)²

Using the identity given in the hint,

(1 - sin²θ)² = (2sin²θ)²

Expanding the square:

(2sin²θ)² = 4sin⁴θ

Let's now reintroduce this outcome into the preceding expression:

E₀ (1 - 2sin²θ + sin⁴θ) = E₀ (2sin²θ)² = E₀ (4sin⁴θ)

Therefore, we have shown that E₀ cos⁴θ = E₀ (1/2 + (cos2θ)/2)².

Hence verified.

Learn more about Trigonometric identity click;

https://brainly.com/question/12537661

#SPJ1

ill give 40 points if someone answers this quickly and correctly.

4 Which graph represents the system of linear inequalities given below?
y ≤ x-3
y > -x + 2​

Answers

Answer: on the line y = x-3 and above the line y = -x + 2.

Step-by-step explanation:

The first inequality, y ≤ x-3, represents a shaded region below or on the line y = x-3. This line has a slope of 1 and y-intercept of -3. It is a straight line that slants upward from left to right.

The second inequality, y > -x + 2, represents a shaded region above the line y = -x + 2. This line has a slope of -1 and y-intercept of 2. It is a straight line that slants downward from left to right.

To determine which graph represents the system of linear inequalities, we need to look for a graph that shows the shaded region below or on the line y = x-3 and above the line y = -x + 2.

the probability that a biased coin lands on heads is 2/5. the coin is spun twice. work out the probability of two heads

Answers

The probability of two heads when a biased coin is spun twice is 0.16.

The first time you flip the coin, the probability of seeing a heads is 2/5. The second time you flip the coin, the probability of seeing a heads is still 2/5 because the probability of a biased coin has not changed over the course of the two flips.

Since each flip is an independent event, you multiply the probabilities together.

The probability of two heads when a biased coin is flipped twice is (2/5) × (2/5) = 4/25 = 0.16.

Therefore, the probability of two heads when a biased coin is spun twice is 0.16.

To learn more about the probability visit:

https://brainly.com/question/11234923.

#SPJ1

Si Guadalupe tiene una masa de 50de kg cuánto pesa en el planeta tierra (g=9.8m/s

Answers

Answer:

Step-by-step explanation:

El peso de un objeto se calcula multiplicando su masa por la aceleración debida a la gravedad. En el caso de Guadalupe, su peso en la Tierra sería 50 kg * 9.8 m/s² = 490 N (newtons).

Other Questions
the current drawn by a 1200-w toaster connected to 120 v is 10 a. the resistance of the toaster coils is All ___________ people are severely underweight, whereas some ___________ patients may have a normal to high body weight. What is the single most potent indicator of an infant's future health? Which of the following raises the largest percentage of federal government? revenue? A. tariffs on imports B. individual income taxes C. excise taxes D. corporate income taxes The HMS Beagle, who path is seen here, circumnavigated the globe. true or false. if the m checkpoint is not cleared, what stage of mitosis will the cell be stuck in? Researchers have found that an octopus given a clear plastic box with three different types of lids and a crab inside will eventually figure out how to get at least one of the lids open to get the crab. They have also shown that after a new octopus observes a veteran octopus (who already knows how to open the box), the new octopus is able to open the box and always uses the same type of lid that the veteran used. What term best describes these behaviors?Multiple ChoiceAssociative learningCognitive learningInnateHabituationImprinting an infant born to an underweight woman is more likely to ______. Madanes contends that the basic tool of strategic therapists is:a. prescribing the symptomb. relabelingc. the directived. empathic listening Find the length of each bolded arc. Round your answer to the nearest hundredth TRUE / FALSE. database programming languages receive all application requests and translate them into the complex operations required to fulfill those requests. Which of the following statements about evolution of behavior is correct?A) Natural selection will favor behavior that enhances survival and reproduction.B) An animal may show behavior that maximizes reproductive fitness.C) If a behavior is less than optimal, it is not completely evolved but will eventually become optimal.D) A and B onlyE) A, B, and C Information is _____ if independent measures, using the same methods, obtain similar results.a. Verifiableb. Consistentc. Understandabled. Relevant y=2\left(\frac{1}{3}\right)^{x} A new drug is developed that prevents the demyelination occurring in the progress of multiple sclerosis. The drug protects the cells responsible for the synthesisand maintenance of myelin in the central nervous system. These cells are most likely which of the following?A- Microglial cellB-oligodendrocyteC- ependymal cellD- astrocyte As compared to acquisition-date accounting for business combinations, subsequent to an acquisition the parent company must additionally report consolidated-A. net income.- B. expenses.- C revenues. .How many different trisomic individuals can be formed in a plant that has a diploid number of 40?Express your answer as an integer. subjects of the islamic empires who were not muslim and enjoyed the status of protected people were called a bus drives for 3 and a half hours at an average speed of 56mph how far does the bus drive? identify a difference between the scotopic system and the photopic system.