question: Teacher asked me this: Solve c = 3*c - 4 for c.
++++++++++
answer: 2

question: Teacher asked me this: Solve -39*c = -29*c + 10 for c.
++++++++++
answer: -1

question: Teacher asked me this: Solve -610*v = -582*v + 308 for v.
++++++++++
answer: -11

question: Teacher asked me this: Solve 0 = 12*c + 22*c - 42*c - 40 for c.
++++++++++
answer:
-5