Help!! on question 13, solve each equation for x.

Solve the system of linear equations. <br> −8x+5y=26<br> 9x−3y=−3

Sloan [31]

Answer: x = 3 and y = 10

Step-by-step explanation:

-8x + 5y = 26 .................. equation 1

9x - 3y = -3 ................ equation 2

Solving the system of linear equations by elimination method.

The means we have to make the coefficient of one of the variable the same in order to eliminate the variable first.

Let us eliminate the variable y first , this means we will multiply equation 1 by 3 and multiply equation 2 by 5. Doing this , we have

-24x + 15y = 78 ............. equation 3

45x - 15y = -15 ................ equation 4

Now that we have the same coefficient , we have to check their signs , if the have the same signs , we will subtract , that is , if both are having positive signs , we will subtract , if both have negative signs , we will also subtract but if their signs differ we will add. Following this rule and considering the equations above , the coefficients of y have different signs , so we will add equation 3 and equation 4 , so we have:

21x = 63

x = 63/21

x = 3

Substitute x = 3 into equation 1 or equation 2 to get the value of y , using equation 2 , we have

9x - 3y = -3

9(3) - 3y = -3

27 - 3y = -3

27+3 = 3y

30 = 3y

30/3 = y

Therefore y = 10

Therefore : x = 3 and y = 10

8 0

3 years ago

<img src="https://tex.z-dn.net/?f=8a%283b%2B6c-7c%29" id="TexFormula1" title="8a(3b+6c-7c)" alt="8a(3b+6c-7c)" align="absmiddle"

tino4ka555 [31]

Answer:

24ab-8ac

Step-by-step explanation:

Assuming you want to simplify it.

Original equation: 8a(3b+6c-7c)

Apply 8a to each variable in the paranthesis: (8a)(3b)+(8a)(6c)+(8a)(-7c)

After multiplication: 24ab+48ac-56ac

Combine like terms: 24ab-8ac

8 0

2 years ago

What is the value of -9 + (-4 + 7) (2)?

RUDIKE [14]

Answer:

try -3

Step-by-step explanation:

5 0

2 years ago

Read 2 more answers

Membership to a music club costs $165. Members

dimulka [17.4K]

Answer:

11 music lessons.

Step-by-step explanation:

We know that membership costs $165 and members pay $25 per music lesson.

So, we can write the following expression:

$165+25m$

The 165 represents the one-time membership fee and the 25m represents the cost for m music lessons.

We know that non-members pay no membership fee but their cost per lesson is $40. So:

$40m$

Represents the cost for non-members for m music lessons.

We want to find how many music lessons would have to be taken for the cost to be the same for both members and non-members. So, we can set the expressions equal to each other:

$165+25m=40m$

And solve for m. Let's subtract 25m from both sides:

$165=15m$

Now, divide both sides by 15:

$m=11$

So, at the 11th music lesson, members and non-members will pay the same.

Further Notes:

This means that if a person would only like to take 10 or less lessons, the non-membership is best because there is no initial fee.

However, if a person would like to take 12 or more lessons, than the membership is best because the membership has a lower cost per lesson than the non-membership.

And we're done!

5 0

3 years ago

the basement has an area of 864 square feet. the width of the basement is two thirds its length. What is the length of the basem

Leno4ka [110]

A = 864
w = 2/3l

A = lw

Plug in what we know:

864 = l(2/3l)

Multiply:

864 = 2/3l^2

Divide 2/3 to both sides or multiply by its reciprocal, 3/2:

864 * 3/2 = l^2

2592/2 = l^2

1296 = l^2

Find the square root of both sides:

l = 36

So the length of the basement is 36 feet.

7 0

3 years ago

Read 2 more answers