Question:
Solve 1070 = 250*f - 143*f for f..

Answer:
10

Question:
Solve -30 = 14*j + 239 + 11 for j..

Answer:
-20

Question:
Solve -201*x + 559 = 64*x - 12161 for x..

Answer:
48

Question:
Solve 277*d - 852*d + 3913 = 408 - 520 for d..

Answer:
7