Question:
Solve 568 - 285 = -9*f + 49 for f..

Answer:
-26

Question:
Solve 50 + 20 = 5*s + 20 for s..

Answer:
10

Question:
Solve 0 = -8*r - 5*r + 26 for r..

Answer:
2

Question:
Solve 63*n + 25423 + 18552 = -1104*n - 57554 for n..

Answer:
-87