Question:
Solve -1424*s = -509*s - 3660 for s..

Answer:
4

Question:
Solve 555*v = 550*v - 20 for v..

Answer:
-4

Question:
Solve 840 = 13*u + 144*u + 373 - 1103 for u..

Answer:
10

Question:
Solve -3505 + 943 = -47*l - 964 for l..

Answer:
34