Write down the solution for this math problem: Solve -12*o = -15*o + 12 for o.
answer: 4

Write down the solution for this math problem: Solve 445*m + 219*m + 216*m + 29920 = 0 for m.
answer: -34

Write down the solution for this math problem: Solve -131*x = -138*x - 21 for x.
answer: -3

Write down the solution for this math problem: Solve 2*k + 18*k + 80 = 0 for k.
answer:
-4