question: Teacher asked me this: Solve -13689 = 268*r + 464*r + 321*r for r.
++++++++++
answer: -13

question: Teacher asked me this: Solve -1456*u + 2959*u = 1833*u + 6270 for u.
++++++++++
answer: -19

question: Teacher asked me this: Solve -777 = -34*q - 1287 for q.
++++++++++
answer: -15

question: Teacher asked me this: Solve 54 = -63*b + 81*b for b.
++++++++++
answer:
3