Question:
Solve -3*i = -i + 16 for i..

Answer:
-8

Question:
Solve 1650*q = 1654*q + 4 for q..

Answer:
-1

Question:
Solve 0 = 42*o + 79*o - 1331 for o..

Answer:
11

Question:
Solve 4878 + 4584 = 498*r for r..

Answer:
19