When is it easier to use the addition method rather than the substitution method to solve a system of equations?

Part a)

There are 52 letters (26 lowercase and 26 uppercase), 10 digits, and 6 symbols. There are 52+10+6 = 68 different characters to choose from.

Adding up those subtotals gives

68^8+68^9+68^10+68^11+68^12 = 9.9207 * 10^21

different passwords possible.

======================================================

Part b)

Let's find the number of passwords where we don't have a special symbol

There are 52+10 = 62 different characters to pick from

Adding those subtotals gives

62^8+62^9+62^10+62^11+62^12 = 3.2792 * 10^21

different passwords where we do not have a special character. Subtract this from the answer in part a) above

( 9.9207 * 10^21)  - (3.2792 * 10^21) = 6.6415 * 10^21

which represents the number of passwords where we have one or more character that is a special symbol. I'm using the idea that we either have a password with no symbols, or we have a password with at least one symbol. Adding up those two cases leads to the total number of passwords possible.

======================================================

Part c)

The answer from part a) was roughly 9.9207 * 10^21

It will take about 9.9207 * 10^21  nanoseconds to try every possible password from part a).

Divide 9.9207 * 10^21  over 1*10^9 to convert to seconds

(9.9207 * 10^21 )/(1*10^9) = 9,920,700,000,000

This number is 9.9 trillion roughly.

It will take about 9.9 trillion seconds to try every password, if you try a password per second.

------

To convert to hours, divide by 3600 and you should get

(9,920,700,000,000)/3600 = 2,755,750,000

So it will take about 2,755,750,000 hours to try all the passwords.

------

Divide by 24 to convert to days

(2,755,750,000)/24= 114,822,916.666667

which rounds to 114,822,917

So it will take roughly 114,822,917 days to try all the passwords.

------

Then divide that over 365 to convert to years

314,583.334246576

which rounds to 314,583

It will take roughly 314,583 years to try all the passwords

------------------------------

All values are approximate, and are roughly equivalent to one another.

A) 9,920,671,339,261,325,541,376 different passwords are available for this computer system.

B) 875,353,353,464,234,606,592 of these passwords contain at least one occurrence of at least one of the six special characters.

C) It would take 314,582.42 years for a hacker to try every possible password.

To determine how many different passwords are available for this computer system; how many of these passwords contain at least one occurrence of at least one of the six special characters; and how long it takes a hacker to try every possible password, assuming that it takes one nanosecond for a hacker to check each possible password, the following calculations must be performed:

Learn more in https://brainly.com/question/19912049

Answer:

7.15 miles

Step-by-step explanation:

4/5 of a mile is equivalent to .8 miles.

32.95

-25.8

7.15

Answer:

Step-by-step explanation:

39.95 - 25.80 = 7.15 miles

Answer:

A. 14z - 28

Step-by-step explanation:

simplify z² - 3z

a. z(z - 3)

the denominator on the right has z(z - 3). but it is also multiplied by (z - 2)

this means the numerator must also be multiplied by (z - 2)

14 x (z - 2) = 14z - 28

hope this helps :)

Hi there! :)

Answer:

x = 1/2 or -7.

Step-by-step explanation:

(I'm assuming the expression is 2x² + 13x - 7 = 0)

Factor the equation to solve for the possible values of "x":

2x² + 13x - 7 = 0

When factored, we get:

(2x - 1) ( x + 7) = 0

Use the Zero-Product property to solve for the roots:

2x - 1 = 0

2x = 1

x = 1/2.

-----------

x + 7 = 0

x = -7.

Therefore, possible values of x are x = -1/2, 7.

Answer:

x = 1/2     x=-7

Step-by-step explanation:

2 x^2  + 13 x − 7 = 0

Factor

(2x-1)(x+7)=0

Using the zero product property

2x-1 =0   x+7=0

2x=1       x =-7

x = 1/2     x=-7

Answer:

All real numbers.

Step-by-step explanation:

As there are no restrictions on the values of x, the domain is all real numbers.

Answer:

All real numbers.

Step-by-step explanation:

Answer: x= -1, z=2, y= -4

Step-by-step explanation:

System of equations:

-5x - 4y - 3z= 15  +

-10x + 4y + 6z= 6

-15x         + 3z = 21  ------>  3 (-5x + z) = 7.3

-5x + z = 7

now,

-10x + 4y + 6z= 6

2(-5x + z) + 4y + 4z = 6

14 + 4y + 4z = 6

7 + 2y + 2z = 3

2y + 2z= -4

y+z=-2

Now we were using the equation: 20x + 4y + 4z = -28

20x + 4(y+z) = 20x -8= - 28

20 x = -20

x= -1

With this we can find y and z

X=-1

-5x + z = 7

z= 2

y+z=-2

y=-4

Finally we have: x= -1, z=2, y= -4

I hope this can help you.

Thank you

Answer:

Option (1)

Step-by-step explanation:

Monica earned a bonus = $60

Per hour earning in addition to bonus = $8.50

Let she worked for 'h' hours this week.

Then total earning from the hourly rate = $8.50h

Total earning for the week = Earning of 'h' hours + Bonus earned

                                             = $(8.50h + 60)

Therefore, Option (1) will represent Monica's earnings for the week.

Answer:

8.50h + 60

Step-by-step explanation:

Answer:

The answer is below

Step-by-step explanation:

The question is not complete, let me solve a question that is exactly like this one.

A certain car model has a mean gas mileage of 34 miles per gallon (mpg) with a standard deviation 5 mpg. A pizza delivery company buys 43 of these cars. What is the probability that the average mileage of the fleet is greater than 33.5 mpg?

Answer:

Given that the mean (μ) is 34 miles per gallon (mpg) with a standard deviation (σ) 5 mpg. The sample (n) is 43.

The z score is used in statistics to determine by how much the raw score is above or below the mean. It is given by:

[tex]z=\frac{x-\mu}{\sigma} \\for\ a \ sample\ size:\\z=\frac{x-\mu}{\sigma/\sqrt{n} }[/tex]

For the average mileage of the fleet is greater than 33.5 mpg (x > 33.5):

[tex]z=\frac{x-\mu}{\sigma/\sqrt{n} }\\z=\frac{33.5-34}{5/\sqrt{43} } =-0.66[/tex]

From the normal distribution table, The probability that the average mileage of the fleet is greater than 33.5 mpg = P(x > 33.5) = P(z > -0.66) = 1 - P(z < -0.66) = 1 - 0.2546 = 0.7454 = 74.54%

Answer:

170

Step-by-step explanation:

3(4)³ - 2(4)² + 10

192 - 32 + 10 = 170

Answer:

a.

[tex]\mathbf{r_1 = (t,0) \implies t = 0 \ to \ 1}[/tex]

[tex]\mathbf{r_2 = (2-t,t-1) \implies t = 1 \ to \ 2}[/tex]

[tex]\mathbf{r_3 = (0,3-t) \implies t = 2 \ to \ 3}[/tex]

b.

[tex]\mathbf{\int \limits _{c} F \ dr =\dfrac{11 \sqrt{2}+11}{6}}[/tex]

Step-by-step explanation:

Given that:

C: counterclockwise around the triangle with vertices (0, 0), (1, 0), and (0, 1), starting at (0, 0)

a. Find a piecewise smooth parametrization of the path C.

r(t) = { 0

If C: counterclockwise around the triangle with vertices (0, 0), (1, 0), and (0, 1),

Then:

[tex]C_1 = (0,0) \\ \\ C_2 = (1,0) \\ \\ C_3 = (0,1)[/tex]

Also:

[tex]\mathtt{r_1 = (0,0) + t(1,0) = (t,0) }[/tex]

[tex]\mathbf{r_1 = (t,0) \implies t = 0 \ to \ 1}[/tex]

[tex]\mathtt{r_2 = (1,0) + t(-1,1) = (1- t,t) }[/tex]

[tex]\mathbf{r_2 = (2-t,t-1) \implies t = 1 \ to \ 2}[/tex]

[tex]\mathtt{r_3 = (0,1) + t(0,-1) = (0,1-t) }[/tex]

[tex]\mathbf{r_3 = (0,3-t) \implies t = 2 \ to \ 3}[/tex]

b Evaluate :

Integral of (x+2y^1/2)ds

[tex]\mathtt{\int \limits ^1_{c1} (x+ 2 \sqrt{y}) ds = \int \limits ^1_{0} \ (t + 0) \sqrt{1} } \\ \\ \mathtt{ \int \limits ^1_{c1} (x+ 2 \sqrt{y}) ds = \begin {pmatrix} \dfrac{t^2}{2} \end {pmatrix} }^1_0 \\ \\ \mathtt{\int \limits ^1_{c1} (x+ 2 \sqrt{y}) ds = \dfrac{1}{2}}[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \int \limits (x+2 \sqrt{y} \sqrt{(\dfrac{dx}{dt})^2 + (\dfrac{dy}{dt})^2 \ dt } }[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \int \limits 2- t + 2\sqrt{t-1} \ \sqrt{1+1} }[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \sqrt{2} \int \limits^2_1 2- t + 2\sqrt{t-1} \ dt }[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \sqrt{2} } \ \begin {pmatrix} 2t - \dfrac{t^2}{2}+ \dfrac{2(t-1)^{3/2}}{3} (2) \end {pmatrix} ^2_1}[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \sqrt{2} } \ \begin {pmatrix} 2 -\dfrac{1}{2} (4-1)+\dfrac{4}{3} (1)^{3/2} -0 \end {pmatrix} }[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \sqrt{2} } \ \begin {pmatrix} 2 -\dfrac{3}{2} + \dfrac{4}{3} \end {pmatrix} }[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \sqrt{2} } \ \begin {pmatrix} \dfrac{12-9+8}{6} \end {pmatrix} }[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \sqrt{2} } \ \begin {pmatrix} \dfrac{11}{6} \end {pmatrix} }[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \dfrac{ \sqrt{2} }{6} \ (11 )}[/tex]

[tex]\mathtt{\int \limits _{c2} (x+ 2 \sqrt{y}) ds = \dfrac{ 11 \sqrt{2} }{6}}[/tex]

[tex]\mathtt{\int \limits _{c3} (x+ 2 \sqrt{y}) ds = \int \limits ^3_2 0+2 \sqrt{3-t} \ \sqrt{0+1} }[/tex]

[tex]\mathtt{\int \limits _{c3} (x+ 2 \sqrt{y}) ds = \int \limits ^3_2 2 \sqrt{3-t} \ dt}[/tex]

[tex]\mathtt{\int \limits _{c3} (x+ 2 \sqrt{y}) ds = \int \limits^3_2 \begin {pmatrix} \dfrac{-2(3-t)^{3/2}}{3} (2) \end {pmatrix}^3_2 }[/tex]

[tex]\mathtt{\int \limits _{c3} (x+ 2 \sqrt{y}) ds = -\dfrac{4}{3} [(0)-(1)]}[/tex]

[tex]\mathtt{\int \limits _{c3} (x+ 2 \sqrt{y}) ds = -\dfrac{4}{3} [-(1)]}[/tex]

[tex]\mathtt{\int \limits _{c3} (x+ 2 \sqrt{y}) ds = \dfrac{4}{3}}[/tex]

[tex]\mathtt{\int \limits _{c} F \ dr =\dfrac{11 \sqrt{2}}{6}+\dfrac{1}{2}+ \dfrac{4}{3}}[/tex]

[tex]\mathtt{\int \limits _{c} F \ dr =\dfrac{11 \sqrt{2}+3+8}{6}}[/tex]

[tex]\mathbf{\int \limits _{c} F \ dr =\dfrac{11 \sqrt{2}+11}{6}}[/tex]

●✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎❀✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎●

          Hi my lil bunny!

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When dividing polynomials using factorization, cancelling identical factors in the denominator and the numerator will give the remainder.

A. remainder

B. dividend

C. quotient

D. divisor

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●✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎❀✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎●

Hope this helped you.

Could you maybe give brainliest..?

❀*May*❀

Answer:

a. remainder

Step-by-step explanation:

took the test

dont leave your house without a vest

or you will get hit in the vital organs in your chest

Answer:

The correct option is b.

Step-by-step explanation:

The complete question is:

Suppose you want to study the length of time devoted to commercial breaks for two different types of television programs. Identify the types of programs you want to study (e.g., sitcoms, sports events, movies, news, children's programs, etc.). How large should the sample be for a specified margin of error.

(a) It depends only on the specified margin of error.

(b) It depends on not only the specified margin of error, but also on the confidence level.

(c) It depends only on the confidence level.

Solution:

The (1 - α) % confidence interval for population mean is:

[tex]CI=\bar x\pm z_{\alpha/2}\times \frac{\sigma}{\sqrt{n}}[/tex]  

The margin of error for this interval is:

 [tex]MOE=z_{\alpha/2}\times \frac{\sigma}{\sqrt{n}}[/tex]

Then the sample size formula is:

[tex]n=[\frac{z_{\alpha/2}\times \sigma}{MOE}]^{2}[/tex]

The sample size is dependent upon the confidence level (1 - α) %, the standard deviation and the desired margin of error.

Thus, the correct option is b.

The size of the sample 'n' depends on not only the specified margin of error, but also on the confidence level.

Given :

Suppose you want to study the length of time devoted to commercial breaks for two different types of television programs.

The following steps can be used in order to determine the size of the sample be for a specified margin of error:

Step 1 - The formula of the confidence interval is given below:

[tex]\rm CI =\bar{x}+z_{\alpha /2}\times \dfrac{\sigma }{\sqrt{n} }[/tex]

Step 2 - Now, for this interval, the formula of margin of error is given below:

[tex]\rm MOE = z_{\alpha /2}\times \dfrac{\sigma}{\sqrt{n} }[/tex]

Step 3 - Solve the above expression for sample size 'n'.

[tex]\rm n = \left(\dfrac{z_{\alpha /2}\times \sigma}{MOE}\right)^2[/tex]

From the above steps, it can be concluded that the correct option is B) It depends on not only the specified margin of error, but also on the confidence level.

For more information, refer to the link given below:

https://brainly.com/question/13990500

Answer:

[tex]a\cdot b[/tex] = 1

Step-by-step explanation:

Given that,

Vector [tex]a=5i+7j[/tex]

Vector [tex]b=-4i+3j[/tex]

We need to find [tex]a{\cdot} b[/tex] means the dot product of a and b. So,

[tex]a{\cdot} b=(5i+7j){\cdot} (-4i+3j)[/tex]

We know that,

[tex]i{\cdot}i, j{\cdot}j,k{\cdot}k=1\ \text{and}\ i{\cdot}j= j\cdot i=0[/tex]

So,

[tex]a{\cdot} b=(5i+7j){\cdot} (-4i+3j)\\\\=5i{\cdot}(-4i)+5i{\cdot} 3j+7j\cdot(-4i)+7j\cdot 3j\\\\=-20+21\\\\=1[/tex]

So, the value of [tex]a\cdot b[/tex] is 1.

Answer:

1

Step-by-step explanation:

Answer:

yd^2

Step-by-step explanation:

I took the test :)

The farmer calculate surface area in unit of [tex]yd^{2}[/tex]

The surface area of any given object is the area or region occupied by the surface of the object.

Thus , The farmer calculate surface area in unit of [tex]yd^{2}[/tex]

Learn more about the surface area here:

https://brainly.com/question/16519513

x = number of 1-cent stamps

y = number of 8-cent stamps

z = number of 12-cent stamps

We have 31 stamps all together, so x+y+z = 31.

"I have 4 more 1-cent stamps than 8-cent stamps" means we have the equation x = y+8. Whatever y is, add 8 to it to get x. Solve for y to get y = x-8.

You also have "twice as many one cent stamps as 12 cent stamps", so x = 2z. Solving for z gets you z = 0.5x

-------------

x+y+z = 31

x+x-8+z = 31 ... y replaced with x-8

x+x-8+0.5x = 31 ... plug in z = 0.5x

2.5x-8 = 31

2.5x = 31+8

2.5x = 39

x = 39/2.5

x = 15.6

Your teacher made a typo somewhere because we should get a positive whole number result for x (since x is a count of how many 1-cent stamps we have).

The number of one-cent stamps is 14.

Total stamps = 31
We have three types of stamps: 1-cent stamps, 8-cent stamps, and 12-cent stamps.

The person has 4 more 1-cent stamps than 8-cent stamps.

The person has twice as many 1-cent stamps as 12-cent stamps.

We have to make equations with the given above statement.

Consider,

1-cent stamp = A

8-cent stamp = B

12-cent stamp = C

4 more 1-cent stamps than 8-cent stamps: A = 4 + B.

A = 4 + B

B = A - 4..........(1)

Twice as many 1-cent stamps as 12-cent stamps: A = 2C.

A = 2C

C = A/2...............(2)

Total number of stamps = 31

A + B + C = 31................(3)

Putting (1) and (2) in (3)

we get,

A + ( A - 4 ) + A / 2 = 31

A + A - 4 + A / 2 = 31

2A - 4 + A / 2 = 31

2A + A / 2 = 31 + 4

(4A + A) / 2 = 35

4A + A = 35 x 2

5A = 70

A = 70 / 5

A = 14

Thus the number of 1-cent stamps is 14.

Learn more about similar problems here:

https://brainly.com/question/16959755

#SPJ5

Answer:

(2,2) (-1,-1)

Step-by-step explanation

i think this is there answer im sorry if im wrong

Answer: 0.0546 and 0.9829

Step-by-step explanation:

solution:

= P( 1.50< Z <2.25 )

= P(Z <2.25 ) - P(Z <1.50 )

Using z table,

= 0.9878-0.9332

=0.0546

b.

= P( -2.12< Z <3.73 )

= P(Z <3.73) - P(Z <-2.12 )

Using z table,

= 0.9999-0.0170

=0.9829

Answer:

Angle E.

Step-by-step explanation:

Hope this helps!

Answer:

Step-by-step explanation:

Area of a triangle = 1/2 * base * height

A = 1/2bh

Rate of change of area is expresssed as dA/dt = dA/db * db/bt

db/dt is the rate at which the base is increasing.

Given db/dt = 18mm/min

A = 1/2*7b

A = 7b/2

dA/db = 7/2

The rate at which the area is changing dA/dt = dA/db * db/bt

dA/dt = 7/2 * 18

dA/dt = 7*9

dA/dt = 63mm/min

Hence the rate at which the area of the triangle is changing is  63mm/min

Answer:

37°

This is because the square indicates a right angle.

53 - 90 = 37

We have,

Now,

AOB + ∠BOC = ∠A0C

⇒ 53° + x° = 90°

⇒ x° = 90° - 53°

⇒ x° = 37°

Answer:

1. add 1/2x to both sides

a. you want to combine the like terms. in this case, it is the x variable.

you are left with 7/6x = 5

2. multiply by 6/7

a. the reciprocal of 7/6 will cancel out the values

Answer: a. paired samples;

Step-by-step explanation:

Paired samples are samples in which each data point in one sample is uniquely paired to a data point in the other sample.

Here, we have a paired sample of fecal boluses for gerbils by characterizing then as "No Drug" and "Drug".

hence, the design of this study is paired samples.

So, option A is correct.

NOTE : Independent samples are opposite of paired samples.

Testing the significance of a correlation require to check relation between two variables.

Answer:

The ball first bounces up to a height of 2 meters, and then falls 2 meters towards the ground

Step-by-step explanation:

Answer:

what is the amount of money Kim earn per hour of babysitting? Also I need to know how much trip cost to find out how many hours she need to work.

Step-by-step explanation:

Answer:

They will need 160 cans to make 5 lbs

32 cans for 1 lbs

Step-by-step explanation:

We can use ratios to solve

8 cans             x cans

--------------- = ---------------

1/4 lbs             5 lbs

Using cross products

8 * 5 = 1/4x

40 = 1/4 x

Multiply each side by 4

4 * 40 = 1/4 x * 4

160 =x

They will need 160 cans to make 5 lbs

8 cans             x cans

--------------- = ---------------

1/4 lbs             1 lbs

Using cross products

8 * 1 = 1/4x

Multiply each side by 4

8*4 = x

32 cans for 1 lbs

Answer:

32 cans per pound of aluminum

160 cans per 5 pounds of aluminum

Step-by-step explanation:

will make it short and simple.

8 empty cans can make 1/4 pound of aluminum.

therefore... 8 x 4 = 32 cans per pound of aluminum.

Number of cans to make 5 pounds of aluminum = 32 x 5

= 160 cans per 5 pounds of aluminum

Answer:

Hey there!

Tangent 70=12/y

Tangent 70y=12

y=12/Tangent 70

y=4.37 cm

Let me know if this helps :)

Answer:

69

Step-by-step explanation:

The order of operations is PEMDAS; parentheses, exponents, multiplication and division, and finally addition and subtraction.

We know that x is the first row, and if there are 30 spots in the first row, then x=30. Using this information, all we have to do now is plug in 30 for x and solve.

[tex]\frac{5(x)}{2} -6[/tex]

[tex]\frac{5(30)}{2}-6[/tex]

[tex]\frac{150}{2}-6[/tex]

[tex]75-6[/tex]

[tex]69[/tex]

Answer:

0

Step-by-step explanation:

-456 +456

( - , + ) = -

so answer is 0

Answer:

0

Step-by-step explanation:

bc i know