Write down the solution for this math problem: Solve 750*r - 125*r + 415*r - 41600 = 0 for r.
answer: 40

Write down the solution for this math problem: Solve -53*w = -60*w - 21 for w.
answer: -3

Write down the solution for this math problem: Solve 191*c = 501*c - 3016 - 4424 for c.
answer: 24

Write down the solution for this math problem: Solve -9*z - 5668 + 5767 = 0 for z.
answer:
11