Question:
Solve -181*v = -149*v - 576 for v..

Answer:
18

Question:
Solve 0 = -1004*l + 2062*l - 1021*l - 703 for l..

Answer:
19

Question:
Solve -13*f - 86*f - 2067 = 60*f for f..

Answer:
-13

Question:
Solve 0 = 15*r - 29*r - 56 for r..

Answer:
-4