math 102
posted by Jennifer .
The outside dimensions of a piece of framework is 24 inches by 20 inches. The area of the picture is 320 square inches. Find the width of the frame itself

if the dimensions of the artwork are x and y, and the frame width is w,
x+2w = 24
y+2w = 20
xy = 320
(242w)(202w) = 320
(12w)(10w) = 80
120  22w + w^2 = 80
w^2  22w + 40 = 0
(w2)(w20) = 0
w = 2 or 20
I leave you to make the proper choice