Q: What is the solution?
Solve -39 - 105 = -24*k for k.

A: 6

Q: What is the solution?
Solve 12*n - 540 = -14*n - 4*n for n.

A: 18

Q: What is the solution?
Solve -153*u + 210525 = -2759*u + 69801 for u.

A:
-54