Solve -144*o + 27*o - 936 = 0 for o.
Solve this plz.

A: -8

Solve 345*b - 3160 + 7197 = -9763 for b.
Solve this plz.

A: -40

Solve -3*r + 6 = -r for r.
Solve this plz.

A:
3