Answer:
1 inch
Explanation:
Factors of 63 are 7 and 9, each of which is 2 more than the dimensions of the photo. Sarah's frame is 1 inch wide.
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A 1-inch wide frame adds 2 inches to length and width.
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Solution using an equation
If you let w represent the width of the frame, the area of the framed photo is ...
(5+2w)(7+2w) = 63
4w^2 +24w -28 = 0 . . . . write in standard form
w^2 +6w -7 = 0 . . . . . . . . divide by 4
(w -1)(w +7) = 0 . . . . . . . . factor
The positive solution to this equation is w=1.
The width of the frame is 1 inch.