Write down the solution for this math problem: Solve -331*r + 168*r + 186*r + 2967 = 0 for r.
answer: -129

Write down the solution for this math problem: Solve -70*r - 67*r + 141*r = 76 for r.
answer: 19

Write down the solution for this math problem: Solve -127123*s - 780 = -127084*s for s.
answer: -20

Write down the solution for this math problem: Solve 112*w = 93*w - 152 for w.
answer:
-8