Q: Solve -c + 12 = 2*c for c.

A: 4

Q: Solve -490*b + 478*b = 24 for b.

A: -2

Q: Solve -5191*c + 281637 = -40049 - 31067 - 233830 for c.

A: 113

Q: Solve 30 - 13 = -2*k - 15 for k.

A:
-16