question: Teacher asked me this: Solve 0 = -6*d + 2*d + 4 for d.
++++++++++
answer: 1

question: Teacher asked me this: Solve 24*i - 30*i = 18 for i.
++++++++++
answer: -3

question: Teacher asked me this: Solve 0*z = 9*z + 18 for z.
++++++++++
answer: -2

question: Teacher asked me this: Solve 20*d = -20*d + 320 for d.
++++++++++
answer:
8