Q: What is the solution?
Solve 25*g - 39*g - 1 = 13 for g.

A: -1

Q: What is the solution?
Solve -4*o + 13*o = 0 for o.

A: 0

Q: What is the solution?
Solve -27 = 42*b - 39*b for b.

A:
-9