Question: What is the solution?

Solve -1189 = -643*y - 2475 for y.

Answer: -2

Question: What is the solution?

Solve 1485 = 18301*s - 18400*s for s.

Answer: -15

Question: What is the solution?

Solve -2*f + 90 = 3*f - 15*f for f.

Answer: -9

Question: What is the solution?

Solve -28*v + 36*v = -45*v + 424 for v.

Answer:
8