Question:
Solve 429*k + 54*k = 249*k + 4680 for k..

Answer:
20

Question:
Solve 0 = 10*f + 26*f + 468 for f..

Answer:
-13

Question:
Solve 4*q + 194 = 150 for q..

Answer:
-11

Question:
Solve 28 - 83 = 11*f for f..

Answer:
-5