Question:
Solve 9 = 2*h + 15 for h..

Answer:
-3

Question:
Solve 81*u + 4083 = 355*u - 2493 for u..

Answer:
24

Question:
Solve -165*m + 409779 = 411924 for m..

Answer:
-13

Question:
Solve 2138 = 513*a + 4787 + 4020 for a..

Answer:
-13