Q: What is the solution?
Solve -641111 + 642351 = 31*z for z.

A: 40

Q: What is the solution?
Solve 4*z - 699 + 790 = -9*z for z.

A: -7

Q: What is the solution?
Solve -884*r = 627*r + 81594 for r.

A:
-54