Question:
Solve 2*o + 2*o - 16 = 0 for o..

Answer:
4

Question:
Solve 0 = 51*k - 95*k for k..

Answer:
0

Question:
Solve 532*r - 325*r + 266*r + 7460 = -273*r for r..

Answer:
-10

Question:
Solve 206*w = 193*w - 78 for w..

Answer:
-6