how to find length when perimeter of rectangle is 20 in. and width is 2/3 its length?
P = 2 [W + L]
20 = 2 [ (2/3)L + L] divide both sides by 2
10 = [ (2/3)L + L] simplify
10 = (5/3)L multiply both sides by (3/5)
(3/5)*10 = L = 6
