question: Teacher asked me this: Solve -6638*a = -6649*a - 165 for a.
++++++++++
answer: -15

question: Teacher asked me this: Solve 280*u - 102*u - 2926 = -200*u - 26362 for u.
++++++++++
answer: -62

question: Teacher asked me this: Solve 1239*r - 21272 + 5716 = 14180 for r.
++++++++++
answer: 24

question: Teacher asked me this: Solve 7*z = 3*z - 16 for z.
++++++++++
answer:
-4