question: Teacher asked me this: Solve -7*d + 0*d = -9*d - 6*d + 312 for d.
++++++++++
answer: 39

question: Teacher asked me this: Solve -84 + 49 - 77 = -16*n for n.
++++++++++
answer: 7

question: Teacher asked me this: Solve -13*r + 1031 = 1473 for r.
++++++++++
answer: -34

question: Teacher asked me this: Solve -1644*d + 714 = -1542*d for d.
++++++++++
answer:
7