Question

Solve system by substitutition or elimination.
9x-8x=9
-18x+16y=-18

Answer 1

1. 9x-8y=9

2. -18x+16y= -18 ⇒ -9x+8y= -9 ⇒ 9x-8y=9

as we see both equations are same, it means the lines overlap and there is infinite number of solutions