Solve -58*b + 3996 = 40*b + 83*b - 107*b for b.
Solve this plz.

A: 54

Solve 1220*u = 101*u + 43641 for u.
Solve this plz.

A: 39

Solve 0 = 39*c - 35 + 74 for c.
Solve this plz.

A:
-1