Sadie computes the perimeter of a rectangle by adding the length, l, and width, w, and doubling this sum. Eric computes the perimeter of a rectangle by doubling the length, l, doubling the width, w, and adding the doubled amounts.
Write an equation for Sadie’s way of calculating the perimeter. Write an equation for Eric’s way as well.
this is just the distributive property.
see what that tells you