Question: What is the solution?

Solve -21*z + 468 = 31*z for z.

Answer: 9

Question: What is the solution?

Solve 77*k + 169 = -592 - 317 for k.

Answer: -14

Question: What is the solution?

Solve -6247 = 588*c - 39*c + 890 for c.

Answer: -13

Question: What is the solution?

Solve 3*v + 21 = 18 for v.

Answer:
-1