Write down the solution for this math problem: Solve -815*d = 653*d - 126033 + 30613 for d.
answer: 65

Write down the solution for this math problem: Solve -3100*o = -3064*o - 792 for o.
answer: 22

Write down the solution for this math problem: Solve 42*u = -32*u - 74 for u.
answer: -1

Write down the solution for this math problem: Solve 79*f + 77*f - 31*f - 10 + 2135 = 0 for f.
answer:
-17