no
3x+12x = 15 15x = 15 x = 1
x+5 = 3x+15 x-3x = 15-5 -2x = 10 x = -5
x=5
4x+7-3x = 15 4x-3x = 15-7 x = 8
x = 2
15
51.
x = 1
3x - 5 + 3x = 1x + 15 3x + 3x -1x = 15 + 5 5x = 20 5x/5 = 20/5 x = 4
3x + 15 = 603x = 60 - 153x = 45x = 45/3Therefore, x = 15.
5x+y=-7 3x+y=15 8=D