Q: What is the solution?
Solve 21*k = -6*k + 11*k - 240 for k.

A: -15

Q: What is the solution?
Solve -35*n = -256*n + 97*n - 744 for n.

A: -6

Q: What is the solution?
Solve 19*s - 16*s = 15 for s.

A:
5