Question:
Solve 0 = 13*b - 5*b - 16 for b..

Answer:
2

Question:
Solve -1953 - 135 = -174*n for n..

Answer:
12

Question:
Solve 428*c + 9169 = 7406 - 23489 for c..

Answer:
-59

Question:
Solve -340 + 1795 + 289 = 109*f for f..

Answer:
16