Question:
Solve -5 = 5*v - 10 for v..

Answer:
1

Question:
Solve -16*d = 31*d + 188 for d..

Answer:
-4

Question:
Solve 872 = 25*s + 672 for s..

Answer:
8

Question:
Solve 40*q + 134 - 11 = -117 for q..

Answer:
-6