Q: What is the solution?
Solve 13*o - 7*o = -12 for o.

A: -2

Q: What is the solution?
Solve 0 = -3*b + 18*b - 30 for b.

A: 2

Q: What is the solution?
Solve 162*m + 1596 = -603*m - 33*m for m.

A:
-2