The length of a rectangle is five times its width. if the perimeter of the rectangle is 96 ft , find its area.

So the perimeter is 2 * length + 2 * width.

So we can assign the width a variable, x, and then for length, 5x, because it's five times the width, or x.

So, 2 * 5x + 2 * x

Or 10x + 2x

12x

Since that equals 96,

12x = 96

/12     /12

x = 8

Area is length times width.

Length is 5x, and width is x.

So basically, 5x * x = area

Or, if you substitute the variable in:

5 * 8 * 8 

320 square feet