Q: What is the solution?
Solve -43*z - 2*z = 405 for z.

A: -9

Q: What is the solution?
Solve -3*r + 9 - 21 = 0 for r.

A: -4

Q: What is the solution?
Solve 80850 = -344699*u + 345749*u for u.

A:
77