question: Teacher asked me this: Solve 0 = -0*o - o for o.
++++++++++
answer: 0

question: Teacher asked me this: Solve -4*c - 28*c = 5*c - 37 for c.
++++++++++
answer: 1

question: Teacher asked me this: Solve 6*r - 77760 + 77826 = 0 for r.
++++++++++
answer: -11

question: Teacher asked me this: Solve -10*t + 121 - 40 = -39 for t.
++++++++++
answer:
12