If a storm window has an area of 400 square inches, what are the dimensions if the window is 12 inches higher than it is wide?

1 Answer
Dec 5, 2016

#14.88061 xx 26.88061# (Approximately)

Explanation:

Let #h# be the height and #w# be the width (both in inches).

Since #"Area" = "Height" xx "Width"#

#hxxw = 400#

Further we are told that
#h=w+12#

Therefore
#(w+12)xxw=400#

#rArr w^2+12w-400=0#

We can then apply the quadratic formula:
#color(white)("XXX")w= (-b+-sqrt(b^2-4ac))/(2a)#

To get
#color(white)("XXX")w=(-6+sqrt(12^2-4 * 1 * 400))/(2 * 1)#
(we can ignore the negative on the square root since #w>=0#)
#color(white)("XXX")~~14.88061#

and since #h=w+12#
#color(white)("XXX")h=26.88061#