Question:
Solve 307885*f - 307892*f = -21 for f..

Answer:
3

Question:
Solve 10*l + 8210300 - 8210280 = 0 for l..

Answer:
-2

Question:
Solve -45*i = -49*i - 20 for i..

Answer:
-5

Question:
Solve 28*y = 50852 - 50572 for y..

Answer:
10