Question

Could someone please help me with these systems. I have to use substitution.
-7x+2y=18
6x+6y=0
Please show your steps so I can learn too. Thank you.

Answer 1

Isolate one term (x or y) in one of the equations

6x+6y=0
6x=-6y
X= -1y

Substitute x=-y into the other equation

-7(-y) + 2y =18

7y + 2y =18

9y=18

Y=2

Substitute y=2 into 6x+6y=0

6x + 6(2) = 0

6x + 12=0

6x= -12

X = -2