Question 166435
Thomas is going to make an open - box by cutting equal squares from th four corners of an 11 inch by 14 inch sheet of cardboard and folding up the sides. If the base is to be 80 square inches, then what size should be cut from each corner?
11x14
base w/corners cut:
(11-2x) by (14-2x)
.
if the base is to be 80 sq inches:
80 = (11-2x)(14-2x)
80 = 154 - 22x -28x + 4x^2
80 = 154 - 50x + 4x^2
80 = 4x^2- 50x + 154 
0 = 4x^2- 50x + 74 
0 = 2x^2- 25x + 37 
Solving using the quadratic equation yields:
x = {10.7845892868043, 1.71541071319574}
.
solution: 
10.78 inches
or 
1.72 inches
.
Details of quadratic equation:
*[invoke quadratic "x", 2, -25, 37 ]