Solve -159 + 117 = 21*u for u.
Solve this plz.

A: -2

Solve -19938*j + 39991*j + 1080 = 19933*j for j.
Solve this plz.

A: -9

Solve 27843*z - 1252*z = 2127280 for z.
Solve this plz.

A:
80