Q: Solve:
Solve -249*z + 261*z = -456*z + 2808 for z.

A: 6

Q: Solve:
Solve 0 = 64*y + 383 + 65 for y.

A: -7

Q: Solve:
Solve -67*f + 19440 + 8721 = 1808*f - 11214 for f.

A:
21