Question:
Solve 49*s + 463 = 23*s + 99 for s..

Answer:
-14

Question:
Solve 3941*n = 3950*n - 18 for n..

Answer:
2

Question:
Solve 46*y = 54*y + 72 for y..

Answer:
-9

Question:
Solve 0 = -21*d + 99 - 99 for d..

Answer:
0