Solve -69025 + 21978 = -6721*o for o.
Solve this plz.

A: 7

Solve 7*f + 4411 = 198*f + 210*f for f.
Solve this plz.

A: 11

Solve 39 = 105*r - 256*r + 341 for r.
Solve this plz.

A:
2