Question

Solve the system of equations below.
x + y = 5
-4x – 2y = -8

Answer 1

x = -1 , y = 6

or (-1, 6)

Explanation:

First solve for "y" in the second equation:

`-4x-2y=-8\\-4x+8=2y\\y=-2x+4`

and now, use this result as a substitution for "y" in terms of "x" in the first equation:

`x+y=5\\x+(-2x+4)=5\\x-2x+4=5\\-x=5-4\\-x=1\\x=-1`

Knowing the value of "x", now we place it in the substitution equation to find "y":

`y=-2x+4\\y=-2(-1)+4\\y=6\\`