Question:
Solve 23 - 7 = -4*l for l..

Answer:
-4

Question:
Solve -141*l + 239 - 295 = 931 for l..

Answer:
-7

Question:
Solve -1384*r + 17804 = -550*r - 3880 for r..

Answer:
26

Question:
Solve 116*f = 136*f - 60 for f..

Answer:
3