SOLUTION: A lady wants to make an​ open-top box for packing baked goods by cutting equal squares from each corner of an 10in by 14in piece of cardboard. She figures that for versatilit

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: A lady wants to make an​ open-top box for packing baked goods by cutting equal squares from each corner of an 10in by 14in piece of cardboard. She figures that for versatilit      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1078267: A lady wants to make an​ open-top box for packing baked goods by cutting equal squares from each corner of an 10in by 14in piece of cardboard. She figures that for versatility the area of the bottom must be 80in squared.
What size of square should she cut from each corner?
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
x, the edge length of the square to remove

%2810-2x%29%2814-2x%29=80
-

2%2A2%2A%285-x%29%287-x%29=2%2A2%2A20
%285-x%29%287-x%29=20
35-12x%2Bx%5E2=20
x%5E2-12x%2B15=0
-
x=%2812%2B-+sqrt%28144-4%2A15%29%29%2F2

x=%2812%2B-+sqrt%28144-60%29%29%2F2

x=%2812%2B-+sqrt%2812%2A7%29%29%2F2

x=%2812%2B-+2sqrt%2821%29%29%2F2
highlight%28x=6-sqrt%2821%29%29

About 1.42 inches