Write down the solution for this math problem: Solve 4078*u + 63100 - 20010 = -231*u for u.
answer: -10

Write down the solution for this math problem: Solve -11450 - 2355 = 251*f for f.
answer: -55

Write down the solution for this math problem: Solve 28*c - 30 - 106 + 584 = 0 for c.
answer: -16

Write down the solution for this math problem: Solve -12*s + 7*s - 10 = 0 for s.
answer:
-2