Question

A stores revenue is the function y = 150x where x is the number of items they sell. Its cost function is

y = 7x + 2200 where x is the number of items they sell. How many items do they have to sell to break-
even? Show how to solve this using inverses and not the table on your calculator.
NO LINKS TO FILES OR ANYTHING LIKE THAT.

Answer 1

9514 1404 393

Answer:

about 15 or 16 items

Explanation:

The break-even point is where revenue is equal to cost.

150x = 7x +2200

143x = 2200 . . . . . . . subtract 7x

x ≈ 15.38 . . . . . . . . . . divide by 143 (multiply by the inverse of 143)

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When 15 items are sold, revenue doesn't quite cover costs. Costs still exceed revenue by 55. When 16 items are sold, revenue exceeds costs by 95. (I would call this the break-even point, because I prefer a slight profit over a slight loss.)