Question:
Solve 18 = -6*f - 12 for f..

Answer:
-5

Question:
Solve -24 = -6*t - 30 for t..

Answer:
-1

Question:
Solve 64*b + 9 = 73*b for b..

Answer:
1

Question:
Solve 40*x + 153 = 23*x for x..

Answer:
-9