4(x - 3) - r + 2x = 5(3x - 7) - 9x
4x - 12 - r + 2x = 15x - 35 - 9x
6x - 12 - r = 6x - 35
6x - 6x - 12 + 35 = r
23 = r <==
with ur answer : -r = -23....u would multiply both sides by -1 to make r positive....resulting in : r = 23....so u basically got the same thing I did...just didn't quite finish