Question

The width of a rectangle is 5 inches less than twice the length. The area of the rectangle is 700 square inches. What is the length of the rectangle?

Answer 1

To calculate the length of the rectangle we let the length be x in, let width be
(2x-5) inches
The area will be given by:
A=length×width
A=x(2x-5)
but
A=700 in²
thus
700=x(2x-5)
700=2x²-5x
this can be written in quadratic form as:
2x²-5x-700=0
solving the quadratic we get:
x=20 or x=-35/2
since the length cannot be negative then:
x=20 in
thus the width will be:
2*20-5
=40-5=35 inches