Write down the solution for this math problem: Solve 664296 = 15398*u + 17580 for u.
answer: 42

Write down the solution for this math problem: Solve 13*b - 9*b + 10*b = 0 for b.
answer: 0

Write down the solution for this math problem: Solve -251*k - 1372 = 60*k + 8580 for k.
answer: -32

Write down the solution for this math problem: Solve -21*q + 6*q = -15 for q.
answer:
1