Question:
Solve -40*n - 6409 = -109*n - 120*n - 32*n for n..

Answer:
29

Question:
Solve 0 = 6*s - 65 + 71 for s..

Answer:
-1

Question:
Solve 200863*z - 138360 = 203169*z for z..

Answer:
-60

Question:
Solve 1197*o = 1179*o + 90 for o..

Answer:
5