Write down the solution for this math problem: Solve 0 = -839*k + 820*k - 323 for k.
answer: -17

Write down the solution for this math problem: Solve 0 = 10*l - 8*l for l.
answer: 0

Write down the solution for this math problem: Solve -112*r + 18*r - 21*r = 49*r + 8692 for r.
answer: -53

Write down the solution for this math problem: Solve -224*a + 2 = -222*a for a.
answer:
1