Write down the solution for this math problem: Solve 30 = 13*x - 48 for x.
answer: 6

Write down the solution for this math problem: Solve -56*c + 683 = 321 + 3274 for c.
answer: -52

Write down the solution for this math problem: Solve -646 - 527 = -223*u + 154*u for u.
answer: 17

Write down the solution for this math problem: Solve -6 = 13*i + 98 for i.
answer:
-8