Write down the solution for this math problem: Solve -12 = 26*k - 90 for k.
answer: 3

Write down the solution for this math problem: Solve -3370 = 786*f + 9206 for f.
answer: -16

Write down the solution for this math problem: Solve -377 + 2454 = 50*r + 17*r for r.
answer: 31

Write down the solution for this math problem: Solve 26*f + 1535 = 1275 for f.
answer:
-10