Question: What is the solution?

Solve 84*y - 2442*y - 4521 - 11985 = 0 for y.

Answer: -7

Question: What is the solution?

Solve -8 = -2*a - 4 for a.

Answer: 2

Question: What is the solution?

Solve 0 = 93*a - 38 - 64 - 1758 for a.

Answer: 20

Question: What is the solution?

Solve 1178*z - 382*z + 16310 = -406 for z.

Answer:
-21