Question:
Solve 149*f - 6340 = -485*f for f..

Answer:
10

Question:
Solve -132405 - 273275 = 3688*r for r..

Answer:
-110

Question:
Solve 0 = 89*s - 163*s + 1776 for s..

Answer:
24

Question:
Solve -254 - 61 + 14 = 43*r for r..

Answer:
-7