15-4a=10x+3 -7-3x=5x+9

Question

15-4a=10x+3
-7-3x=5x+9

Answer 1

15-4x=10x+3
10x+4x=15-3
14x=12
x=12/14
x=6/7

-7-3x=5x+9
5x+3x=-7-9
8x=-16
x=-16:8
x=-2