Question

5. Sara has a photo that is 5 inches by 7 inches. When she adds a frame

to it, she gets an area of 63 square inches. How wide is the frame
inches
Answer:

Answer 1

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.