Solve 71*u = 75*u + 12 for u.
Solve this plz.

A: -3

Solve -377*f - 209*f + 6 = 6452 for f.
Solve this plz.

A: -11

Solve 8*b + 249 - 297 = 0 for b.
Solve this plz.

A:
6