Solve 23*y + 27*y = 21*y + 261 for y.
Solve this plz.

A: 9

Solve 64*r - 3460 = -3844 for r.
Solve this plz.

A: -6

Solve -42075 = -8214*k + 7719*k for k.
Solve this plz.

A:
85