SOLUTION: The area of the window is 20 square feet. Find its dimensions (in ft). A rectangular window has two labeled sides. One of the shorter, vertical sides is labeled x ft. One of t

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: The area of the window is 20 square feet. Find its dimensions (in ft). A rectangular window has two labeled sides. One of the shorter, vertical sides is labeled x ft. One of t      Log On


   

Question 1156081: The area of the window is 20 square feet. Find its dimensions (in ft).
A rectangular window has two labeled sides.
One of the shorter, vertical sides is labeled x ft.
One of the longer, horizontal sides is labeled 2x − 3 ft.
smaller value
ft
larger value
ft
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

The area of the window is
20square feet
A rectangular window: the area is length%2Awidth

One of the shorter, vertical sides is labeled x ft.
One of the longer, horizontal sides is labeled 2x+-3+ft.

x%282x-3%29=20
2x%5E2-3x=20
2x%5E2-3x-20=0......factor
2x%5E2%2B5x-8x-20=0
%282x%5E2-8x%29%2B%285x-20%29=0
2x%28x-4%29%2B5%28x-4%29=0
%28x+-+4%29+%282x+%2B+5%29+=+0
we need only positive solution
=>x=4
=> then 2x+-3+=2%2A4-3=5
the shorter vertical side is 4 ft.
the longer horizontal side is 5+ft.