Question:
Solve 0 = b - 7*b - 12 for b..

Answer:
-2

Question:
Solve 369*a - 324 + 652 + 1517 = 0 for a..

Answer:
-5

Question:
Solve 201 = 151*f + 352 for f..

Answer:
-1

Question:
Solve -45 = 6*r - 15 for r..

Answer:
-5