Question: What is the solution?

Solve 57 = -25*z - 168 for z.

Answer: -9

Question: What is the solution?

Solve 97*o + 1991 = -710*o + 16201 + 1123 for o.

Answer: 19

Question: What is the solution?

Solve -19 = 2*a - 13 for a.

Answer: -3

Question: What is the solution?

Solve -301*v = -306*v + 80 for v.

Answer:
16