Question

Use addition or substitution to find the value of x for this set of equations. 4x+13y=40 4x+3y=-40

Answer 1

You can subtract the second expression form the first.

Answer 2

i don't understand how would i do that?

Answer 3

4x + 13y = 40
4x + 4y = -40

use subtraction to cancel the x

4x + 13y = 40
4x + 3y = -40
=========
0 + 10y = 80

10y = 80
y = 80/10
y = 8

now use this to solve for x

4x + 3y = -40

4x + 3(8) = -40
4x + 24 = -40
4x = -40 - 24
4x = -64
x = -64/4
x = -16

do you get that @hispanicgal5

Answer 4

ohhhh i get it thank you! @lgbasallote

Answer 5

Use addition or substitution to find the value of x for this set of equations.
12x - 5y = 30
y = 2x - 6

Answer 6

put your y in and solve for x
12x-5(2x-6)=30
12x-10x-30=30
2x=60
x=30
now put that in for x in the equation y=2x-6 and you have your answer