Question

A company models its net income, in thousands of dollars, with the function f(x) = 9x² – 54x – 144, where x is the number of units of its product sold. How many units of its product does the company need to sell in order for the net income to equal $0?

Answer 1

8

Explanation:

Income = 0

so 0 = 9x^2 - 54x - 154

you can go straight to the Quadratic Formula to find the answer, or you can try factoring as follows ....

divide both sides of the equation by 9 to get

x^2 -6x -16 = 0 which easily factors to :

(x -8)(x+2) = 0 <===== this shows x = 8 or -2(throw out)