question: Teacher asked me this: Solve 17180 - 67592 = 7559*u + 100768 for u.
++++++++++
answer: -20

question: Teacher asked me this: Solve 0*r + 18*r = -21*r + 507 for r.
++++++++++
answer: 13

question: Teacher asked me this: Solve 2113*z - 84 = 2107*z for z.
++++++++++
answer: 14

question: Teacher asked me this: Solve 57*f + 27*f = -336 for f.
++++++++++
answer:
-4