Question:
Solve 22 = 7*h - 20 for h..

Answer:
6

Question:
Solve 0 = -12*p + 9*p + 12 for p..

Answer:
4

Question:
Solve 0 = 5*v - 1 - 4 for v..

Answer:
1

Question:
Solve -99*l - 531*l - 822 = -219*l for l..

Answer:
-2