Question

Solve by the substitution method.
x+3y=12
8x+2y=-36

Answer 1

x+3y=12 ...........eq#1
8x+2y=-36..........eq#2
take eq#1, and separate x
x=12-3y ........eq#3
put eq#3 into EQ#2
8(12-3y)+2y=-36
96-24y+2y=-36
96+36=22y

y=132\22
y=6
now put the value of y into EQ # 3
x=12-3(6)
x=12-18
x=-6
so the solution set is { (-6 , 6 ) }
this is the correct answer