Question:
Solve -20*r - 143 = -139 - 284 for r..

Answer:
14

Question:
Solve -72 = 6*m - 96 for m..

Answer:
4

Question:
Solve 12*u - 45 - 6 - 33 = 0 for u..

Answer:
7

Question:
Solve 15 = 2*g + 21 for g..

Answer:
-3