Question

P(x)=0.2x^2+20x-4 where x is the number of units sold. How many units need to be sold for the business to make a profit of $101?

Answer 1

5

Explanation:

Given the profit equation ;P(x)

x = number of units sold

P(x) = profit made

P(x) = 101

101 = 0.2x^2+20x-4

0.2x^2+20x-4 - 101

0.2x² + 20x - 105 = 0

Using the formula:

-b±[sqrt(b² - 4ac) / 2a]

Where ;

a = 0.2 ; b = 20, c = - 105

Using the quadratic equation solver to save time :

The roots are :

-105 and 5

Items sold cannot be negative ;

Hence, x = units sold = 5