Solve each system of equation by substitution y = -2x + 4 y= -6. y = 4x - 5 x= 2. y = 5x - 8 y = x

1. Set y = -6
-6 = -2x + 4 then move 4 over
-10 = -2x then divide both sides by -2
5 = x

2. Set x = 2
y = 4(2) - 5
y = 8 - 5
y = 3

3. Set y = x
x = 5x - 8 from here you want to isolate x by adding 8 to the left side and subtracting one x from the right side
8 = 5x - x
8 = 4x now you want to divide both sides by 4
2 = x
Now we want to solve for why, so in the original equation set x = 2
y = 5(2) - 8
y = 10 - 8
y = 2
So when x = 2, y =2

CP - the cost of painting the house for Painting USA company [$]
cP = 75 + 25 * 25 = 75 + 625 = 700 [$]
cU - the cost of painting the house for Upscale Home Painting company [$]
cU = 0 + 40 * 25 = 1000 [$]

cP < cU
The most cost effective is Painting USA company.

n - number of houres required to paint the house if the same cost for both companies
75 + 25 * n = 40 * n
40 n - 25n = 75
15n = 75  /:15
n = 5
The cost of paining the house is the same for both companies if the number of houres required to paint the house is 5.