SOLUTION: A bookstore can purchase several calculators for a total cost of $160. If each calculator cost $4 less, the bookstore could purchase 2 additional calculators at the same total cost
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Question 1116968: A bookstore can purchase several calculators for a total cost of $160. If each calculator cost $4 less, the bookstore could purchase 2 additional calculators at the same total cost. How many calculators can be purchased at the regular price? Found 2 solutions by ankor@dixie-net.com, josgarithmetic:Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! A bookstore can purchase several calculators for a total cost of $160.
If each calculator cost $4 less, the bookstore could purchase 2 additional calculators at the same total cost.
How many calculators can be purchased at the regular price?
:
let c = no. of calc purchased at regular price
then = original price per calc
: - 4 =
multiply by c(c+2), cancel denominators
160(c+2) - 4c(c+2) = 160c
160c + 320 - 4c^2 - 8c = 160c
subtract 160c to both sides
320 - 4c^2 - 8c = 0
0 = 4c^2 + 8c - 320
simplify, divide by 4
c^2 + 2c - 80 = 0
factors to
(c+10)(c-8) = 0
positive solution
c = 8 calculators at regular price
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