Q: What is the solution?
Solve 4*r - 9 + 1 = 0 for r.

A: 2

Q: What is the solution?
Solve -161 = -5*a - 186 for a.

A: -5

Q: What is the solution?
Solve 128*o + 260 + 1148 = -2020 - 3612 for o.

A:
-55