Question

Suppose that the length of a rectangle is 4 times the width. If the area is 900 square feet, then what is the width of the rectangle, in feet?

Answer 1

Width 15 feet

Explanation:

Use formula

`A_(rectangle)=\text{Width}\cdot \text{Length}`

Let x feet be the width of the rectangle.

If the length of a rectangle is 4 times the width of the rectangle, then the length is 4x feet.

The area of the rectangle is 900 square feet, so

`900=x\cdot 4x\\ \\900=4x^2\\ \\x^2=225\ [\text{Divided by 4}]\\ \\x=\pm 15`

The width cannot be negative, then x=15 feet and 4x=60 feet.