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Sally has a photograph that has an area of 35 square inches. She creates 2 enlargements of the photograph. The enlargements have areas of 140 square inches and 560 square inches. In each photograph, the length is 1 2/5 times the width. Select which of thr following could be th dimensions of the original photograph or one of the enlargements. Mark all that apply

5 inches by 7 inches
20 inches by 28 inches
7 inches by 20 inches
21 inches by 15 inches
10 inches by 14 inches

Respuesta :

carlosego
The area of the photograph is:
 A = (w) * (l)
 Where,
 w: width
 l: long
 Substituting:
 35 = (w) * (1.4w)
 35 = 1.4 * w ^ 2
 w = root (35 / 1.4)
 Dimensions of the original photograph:
 w = 5 in
 l = 1.4 * (5) = 7 in
 Dimensions of extension 1:
 k = (140) / (35) = 4
 w = 4 * 5 = 20 in
 l = 4 * 7 = 28 in
 Dimensions of extension 2: 
 k = (560) / (35) = 16
 w = 16 * 5 = 80 in
 l = 16 * 7 = 112 in

 Answer:
 5 inches by 7 inches
 20 inches by 28 inches

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