Q: Solve:
Solve 15*r + 37*r + 280 = 87*r for r.

A: 8

Q: Solve:
Solve 111*f - 722 = -190*f - 60*f for f.

A: 2

Q: Solve:
Solve 1497*c - 1491*c = 48 for c.

A:
8