Question:
Solve -220*i = -31*i - 1890 for i..

Answer:
10

Question:
Solve -2*w = -17*w - 75 for w..

Answer:
-5

Question:
Solve -105*r + r + 8 = 944 for r..

Answer:
-9

Question:
Solve 0 = -9*b + 2*b for b..

Answer:
0