Q: Solve:
Solve 0 = -553*c + 556*c + 21 for c.

A: -7

Q: Solve:
Solve 209 = 15*b - 106 for b.

A: 21

Q: Solve:
Solve -211*w - 477*w + 158752 = 688*w - 864 for w.

A:
116