Help! Solve using the Addition Method 2x-y=8 4x+3y=36?

Question

and

2x+2y=19
2x-2y=36

Answer 1

The goal is to remove one of the variables. One way to do this is to multiply the first equation on both sides by -2.

(-2)(2x-y)=(8)(-2)
4x+3y=36
_____________
-4x+2y = -16
4x+3y =36
__________
5y = 20
y =4

Substitute 4 for y in both equations & then determine x.

Read this link for a detailed explanation & example: http://mathforum.org/library/drmath/view/53127.html

Hint for the 2nd problem: by adding the equations as they are you will eliminate y & solve for x.

Answer 2

4x = 55

x = 13.75

2(13.75) + 2y = 19

27.5 + 2y = 19

2y = -8.5

y = -4.25