Q: What is the solution?
Solve -57*c + 50*c = -21 for c.

A: 3

Q: What is the solution?
Solve 9*h = 27*h + 21127 - 21289 for h.

A: 9

Q: What is the solution?
Solve -665*k - 467809 + 407294 = 0 for k.

A:
-91