Q: Solve 0 - 21 = -21*c for c.

A: 1

Q: Solve 6*a = -5*a - 110 + 22 for a.

A: -8

Q: Solve 13238*l + 692790 = 6640*l for l.

A: -105

Q: Solve -59*p - 57 = -78*p for p.

A:
3