Question: What is the solution?

Solve 1259*s = 411*s + 42417 - 16977 for s.

Answer: 30

Question: What is the solution?

Solve 20 = 120*x - 124*x for x.

Answer: -5

Question: What is the solution?

Solve -17499*z = -17151*z + 12876 for z.

Answer: -37

Question: What is the solution?

Solve 0 = -2*f + 380 - 388 for f.

Answer:
-4