Question:
Solve -285*d - 73*d + 3728 = 108*d for d..

Answer:
8

Question:
Solve 16 = 5*b + 4*b + 106 for b..

Answer:
-10

Question:
Solve 11839*r = -1406*r - 211920 for r..

Answer:
-16

Question:
Solve -17*i - 13*i + 133 = 13 for i..

Answer:
4