Write down the solution for this math problem: Solve 31*u = 48*u - 51 for u.
answer: 3

Write down the solution for this math problem: Solve 3919 = 1435*n - 43436 for n.
answer: 33

Write down the solution for this math problem: Solve 1206*u - 616*u - 627*u + 518 = 0 for u.
answer: 14

Write down the solution for this math problem: Solve -71 = -0*l - 2*l - 47 for l.
answer:
12