question: Teacher asked me this: Solve -3*y + 13*y = -30 for y.
++++++++++
answer: -3

question: Teacher asked me this: Solve -7*s = -s + 24 for s.
++++++++++
answer: -4

question: Teacher asked me this: Solve 629*k - 636*k + 14 = 0 for k.
++++++++++
answer: 2

question: Teacher asked me this: Solve -9*c + 136 - 127 = 0 for c.
++++++++++
answer:
1