Q: What is the solution?
Solve 22*s + 509 = 157 for s.

A: -16

Q: What is the solution?
Solve -308*r + 75 = -119*r + 357*r + 621 for r.

A: -1

Q: What is the solution?
Solve 0 = 5*o - 6*o + 5 for o.

A:
5