Write down the solution for this math problem: Solve 51*k - 149*k = 490 for k.
answer: -5

Write down the solution for this math problem: Solve -864*i + 445*i + 20112 = 0 for i.
answer: 48

Write down the solution for this math problem: Solve -619*n + 646*n = 7 + 884 for n.
answer: 33

Write down the solution for this math problem: Solve 9*x + 72 - 36 = 0 for x.
answer:
-4