A frame that measures 13 inches by 11 inches is of uniform width. The area of the picture inside is 35 square inches. What is the width of the frame?

Answer 1

13(11)-35

= 143-35 = 108

= 2(13)w +2(11-2w)w = 108

26w +22w - 4w^2 = 108

4w^2 -48w = -108

w^2 -12w =-27

w^2 -12w +36 =-27+36 = 9

w-6 = +/-3

w = 3 or 9, but 9 is impossible

so

w = 3 inches = width of the frame

11 by 13

means

11-6 by 13-6 = 5 by 7= 5(7)

=35 square inches for the picture