question: Teacher asked me this: Solve 21 = -10*o + 81 for o.
++++++++++
answer: 6

question: Teacher asked me this: Solve -11*p - 5 = -16*p for p.
++++++++++
answer: 1

question: Teacher asked me this: Solve 98*r = -70*r - 1757 + 413 for r.
++++++++++
answer: -8

question: Teacher asked me this: Solve 3258*f = -3715*f + 502056 for f.
++++++++++
answer:
72