Question:
Solve 655*f - 623*f - 1440 = 0 for f..

Answer:
45

Question:
Solve 391*d + 27120 = -1222*d + 288*d - 370*d for d..

Answer:
-16

Question:
Solve 3961*x - 3965*x + 88 = 0 for x..

Answer:
22

Question:
Solve 7*u = 1198 - 1492 for u..

Answer:
-42