Answer:

Step-by-step explanation:
x² = 19x + 12
⇔ x² - 19x - 12 = 0
Calculating the discriminant :
b² - 4ac = (-19)² - 4×1×(-12) = 409
The discriminant is positive ,then the equation has two solutions.

To start break even they need to sell 100 but if they want to make profit they need to sell 101 because you can use the equation y = .75x - 55