Question

The length of a rectangle is 1 ft less than twice its

width. If the area of the rectangle is 78 ft^2 ,what
are the dimensions of the rectangle?

Answer 1

Width: 13/2 ft.

Length: 12 ft.

Explanation:

Let's assume the width is x

This means that the length is 2x-1, because it it one less than double the width.

The formula for the area of a rectangle is length*width, so

(2x-1)*x=78

Now let's solve for x

2x^2-x=78

2x^2-x-78=0

Use the quadratic formula

x=13/2 and x=-6

x cannot be negative, so we can rule out x=-6 and are left with x=13/2.

Substituting x back into our original assumptions, we now know that

The width is x=13/2 and

The length is 2x-1=2(13/2)-1=12

Final answer: The width is 13/2 ft. and the length is 12 ft.