Question:
Solve -8 = -5*a + 7*a for a..

Answer:
-4

Question:
Solve -1500*v + 3261 = 12261 for v..

Answer:
-6

Question:
Solve 0 = 126*l - 117*l - 9 for l..

Answer:
1

Question:
Solve 0 = -2*y + y - 1 for y..

Answer:
-1