Q: Solve:
Solve 4*p = -2*p - 18 for p.

A: -3

Q: Solve:
Solve 4 = 13*r + 30 for r.

A: -2

Q: Solve:
Solve -557*o - 1522*o - 16677 - 16086 = 501 for o.

A:
-16