Question: What is the solution?

Solve -4*f = 71 - 91 for f.

Answer: 5

Question: What is the solution?

Solve -4*u = u for u.

Answer: 0

Question: What is the solution?

Solve 0 = -1042*b - 65771 + 9503 for b.

Answer: -54

Question: What is the solution?

Solve 0 = -3*b - 7*b - 40 for b.

Answer:
-4