If the inventor in exercise 53 charges $4 per unit, then her?

Question

P(x) 2.25x -7000
(a) What is her profit if she sells 2000 units?
(b) What is her profit if she sells 5000 units?
(c) What is the break-even point for sales?

Answer 1

You've got conflicting information. The title says that she is now charging $4. The text says 2.25x, which indicates that she's charging $2.25/unit. The answer for $2.25/unit is:

a) (2.25 * 2,000) - 7,000 = -2,500
b) (2.25 * 5,000) - 7,000 = 4,250
c) (2.25x-7,000) = 0
2.25x = 7,000
x = 7,000/2.25
x = 3111.11

The answer if it is $4 is:


a) (4 * 2,000) - 7,000 = 1,000
b) (4 * 5,000) - 7,000 = 13,000
c) (4x-7,000) = 0
4x = 7,000
x = 7,000/4
x = 1750