Question:
Solve -4 + 19 = -5*u for u..

Answer:
-3

Question:
Solve -219*b + 2108 = 170*b + 209*b - 530*b for b..

Answer:
31

Question:
Solve -2*y - 3*y = -10 for y..

Answer:
2

Question:
Solve -312*y + 513*y - 3073 + 2955 = -8359 for y..

Answer:
-41