Question:
Solve 110 = 20*a - 31 - 59 for a..

Answer:
10

Question:
Solve 170 = 6*x + 176 for x..

Answer:
-1

Question:
Solve -258 + 62 = -12*r + 176 for r..

Answer:
31

Question:
Solve -155*o + 477*o - 304 = -4812 for o..

Answer:
-14