Question:
Solve -10*u = -5*u - 20 for u..

Answer:
4

Question:
Solve -122*j + 5195 - 5805 = 0 for j..

Answer:
-5

Question:
Solve 212 = 7*n + 10*n + 161 for n..

Answer:
3

Question:
Solve 0 = -9*d + 3061 - 3007 for d..

Answer:
6