Question:
Solve 50 - 66 = -4*b for b..

Answer:
4

Question:
Solve 47*w + 20 = 52*w for w..

Answer:
4

Question:
Solve 7*d = -5*d - 2170 + 1378 for d..

Answer:
-66

Question:
Solve -8 = 9*j + 46 for j..

Answer:
-6