Solve 10997 + 9842 + 1366 = -865*u - 1150 for u.
Solve this plz.

A: -27

Solve -4*k + 25 = 21*k for k.
Solve this plz.

A: 1

Solve 6*f = 13*f + 42 for f.
Solve this plz.

A:
-6