Solve 5377 = -2562*r + 40085 + 12100 + 4432 for r.
Solve this plz.

A: 20

Solve -399*a = 482*a - 881 for a.
Solve this plz.

A: 1

Solve 5956*r - 5965*r + 81 = 0 for r.
Solve this plz.

A:
9