Question:
Solve -20*k - 21*k + 88 = 3*k for k..

Answer:
2

Question:
Solve 405*f - 7020 = 15*f for f..

Answer:
18

Question:
Solve -58*v + 534 = -104 for v..

Answer:
11

Question:
Solve 6*o = -o + 2*o for o..

Answer:
0