Write down the solution for this math problem: Solve -223*k = -211*k - 72 for k.
answer: 6

Write down the solution for this math problem: Solve -20186*l + 697 = -20227*l for l.
answer: -17

Write down the solution for this math problem: Solve 145*n = 421762 - 411032 for n.
answer: 74

Write down the solution for this math problem: Solve 21*r + 503 = -55*r - 105 for r.
answer:
-8