Question:
Solve 42*s - 268 = 152 for s..

Answer:
10

Question:
Solve 0 = 9*x - 5*x + 8 for x..

Answer:
-2

Question:
Solve 0 = 6*p - 226 + 274 for p..

Answer:
-8

Question:
Solve 1 - 1 = 20*r for r..

Answer:
0