question: Teacher asked me this: Solve 18*c + 39 = 129 for c.
++++++++++
answer: 5

question: Teacher asked me this: Solve -20*w - 84 = 8*w for w.
++++++++++
answer: -3

question: Teacher asked me this: Solve -5*f + 21 - 16 = 0 for f.
++++++++++
answer: 1

question: Teacher asked me this: Solve -4031543*i + 4031742*i = -6541 - 19329 for i.
++++++++++
answer:
-130