Solve 87 = 66*k + 21 for k.
Solve this plz.

A: 1

Solve 3485*s - 18439 - 7956 = -20809 - 124076 for s.
Solve this plz.

A: -34

Solve 134 = 65*t - 76*t - 31 for t.
Solve this plz.

A:
-15