A picture that measures 9 inches by 7 inches is placed in a frame of uniform width. If the area of the frame and picture together is 323 square inches, what is the width of the frame?

Answer 1

(9+2w)(7+2w) =343

63 + 32w + 4w^2 = 343

4w^2 +32w - 280 = 0

w^2 +8w -70 = 0

w^2 +8w +16 = 70+16

(w+4)^2 = 86

w+4 = sqr86

w = sqr86 -4

w= about 9.27-4

w = about 5.27 inches wide frame