Question: What is the solution?

Solve -9*f = -90 + 36 for f.

Answer: 6

Question: What is the solution?

Solve 18 = 107*t - 113*t for t.

Answer: -3

Question: What is the solution?

Solve -4*z + 24 = 16 for z.

Answer: 2

Question: What is the solution?

Solve -158*u = 159*u + 201*u + 364 + 154 for u.

Answer:
-1