Question:
Solve 21*j - 38*j = -15*j + 38 for j..

Answer:
-19

Question:
Solve -20*l - 99*l = -264*l + 1015 for l..

Answer:
7

Question:
Solve 0 = 38*d + 7*d - 360 for d..

Answer:
8

Question:
Solve -34 = -84*s + 29 + 189 for s..

Answer:
3