Question:
Solve 3*f - 4 = -19 for f..

Answer:
-5

Question:
Solve -15*a = 7 - 97 for a..

Answer:
6

Question:
Solve 50 = -1517*z + 1515*z for z..

Answer:
-25

Question:
Solve -30*j - 71*j = 2525 for j..

Answer:
-25