Question: What is the solution?

Solve 115*r - 7239325 + 7242775 = 0 for r.

Answer: -30

Question: What is the solution?

Solve -139*z = 169*z - 229*z - 1422 for z.

Answer: 18

Question: What is the solution?

Solve -4119 = 185*v + 3466 for v.

Answer: -41

Question: What is the solution?

Solve -88*r = -521 + 169 for r.

Answer:
4