Equation 1) y = 3 - x
Equation 2) 8x + y = -4
Rearrange equation 1 so that x and y are on the same side. To do so, you add x to both sides.
1) x + y = 3
2) 8x + y = -4
Subtract equations from each other.
-7x = 7
Divide both sides by -7.
x = 1
Plug in 1 for x in the first equation.
y = 3 - x
y = 3 - 1
Simplify.
y = 2
(1, 2) ==> x = 1, y = 2
~Hope I helped!~
