Question:
Solve -30 = -4*d - d for d..

Answer:
6

Question:
Solve 2092*a - 139765 + 20521 = 0 for a..

Answer:
57

Question:
Solve 836*s = 762 + 7491 + 3451 for s..

Answer:
14

Question:
Solve 1 = -5*a - 9 for a..

Answer:
-2