Q: Solve -8*r + 0 + 0 = 0 for r.

A: 0

Q: Solve 6513 = -40*b - 265*b - 2942 for b.

A: -31

Q: Solve 28*w = -47*w - 525 for w.

A: -7

Q: Solve -3442 = -13899*c + 14005*c + 1116 for c.

A:
-43