Write down the solution for this math problem: Solve 12 = -7*u + 5 for u.
answer: -1

Write down the solution for this math problem: Solve 1210 + 220 = 193*x - 219*x for x.
answer: -55

Write down the solution for this math problem: Solve 123 = 29*x + 252 + 219 for x.
answer: -12

Write down the solution for this math problem: Solve 188 - 168 = -52*c - 656 for c.
answer:
-13