Question:
Solve -3*j = 192 - 189 for j..

Answer:
-1

Question:
Solve 21*b = 63 + 35 + 28 for b..

Answer:
6

Question:
Solve 78*j + 5783 = -84*j - 2402 + 85 for j..

Answer:
-50

Question:
Solve 0 = 3*b - 57 + 69 for b..

Answer:
-4