P = 2l + 2w
38 = 2l + 2w
l = w + 3 , (the length is 3 inches more than the width)
then substitute w + 3 to l in 38 = 2l + 2w
38 = 2(w + 3) + 2w
38 = 2w + 6 + 2w
38 = 4w + 6, then take away 6 from both sides
32 = 4w, then divide both sides by 4
w = 8 inches (width)