Question:
Solve -190 = -45*b + 125 for b..

Answer:
7

Question:
Solve 26*q - 28 = 33*q for q..

Answer:
-4

Question:
Solve -149 + 270 = -l + 142 for l..

Answer:
21

Question:
Solve -39*r + 66*r + 86*r - 3968 = 5185 for r..

Answer:
81