question: Teacher asked me this: Solve 2515*r + 3 = 2514*r for r.
++++++++++
answer: -3

question: Teacher asked me this: Solve 0 - 1 = -141*o - 1 for o.
++++++++++
answer: 0

question: Teacher asked me this: Solve 788 = -42*a - 52 for a.
++++++++++
answer: -20

question: Teacher asked me this: Solve -38*a + 219 = 447 for a.
++++++++++
answer:
-6