Question:
Solve 19*n - 8*n + 51 = 28*n for n..

Answer:
3

Question:
Solve -8 = -8*l - 0 for l..

Answer:
1

Question:
Solve 0 = -4*s + 7*s - 1040 + 1013 for s..

Answer:
9

Question:
Solve 30 = 9*d + 26*d + 345 for d..

Answer:
-9