4x + 8y = 20
- 4x + 2y = -30
find y first
in order to find y eliminate x
add the two equations together
4x+-4x+8y+2y= 20+-30
4x-4x+8y+2y= 20-30
10y= -10
divide both sides by 10 to get y by itself
10y/10= -10/10
y= -1
find x by using the substitution method
- 4x + 2y = -30
-4x+2(-1)=-30
-4x-2= -30
move -2 to the other side
sign changes from -2 to +2
-4x-2+2= -30+2
-4x= -28
divide both sides by -4
-4x/-4= -28/-4
x= 7
answer:
(7,-1)
