Question: What is the solution?

Solve 0 = 394031*r - 394517*r - 13608 for r.

Answer: -28

Question: What is the solution?

Solve 1435 - 293 = -105*y - 958 for y.

Answer: -20

Question: What is the solution?

Solve -2551*z = -2541*z - 80 for z.

Answer: 8

Question: What is the solution?

Solve -35*z + 0*z + 240 = -19*z for z.

Answer:
15