Question: What is the solution?

Solve -4*f = -14*f + 20 for f.

Answer: 2

Question: What is the solution?

Solve -12*f + 6*f - 7*f = 0 for f.

Answer: 0

Question: What is the solution?

Solve 91 = 31*f - 44*f for f.

Answer: -7

Question: What is the solution?

Solve 55*p = 58*p - 12 for p.

Answer:
4