Question

A picture is 7 inches wide and 9 inches long. A photographer enlarges it so it is 31.5 inches wide and 40.5 inches long. What scale factor was used to enlarge the picture? 9 over 7 7 over 9 31.5 over 7 7 over 31.5

Answer 1

Answer:The scale factor by which the picture has been enlarged is 3.5

Explanation:

It is given that the width of the picture is 5 inches and the length of the picture is 17.5 inches.

Length (l) = 7 inches

Width (b) = 5 inches

The picture is a rectangle, so the area of the picture will be the product of the length and the width, that is Area = 7 * 5 = 35 square inches.

The picture has been enlarged, let k be the scale factor that has been used to enlarge the picture.

The width has been enlarged to 17.5 inches

And the length has been enlarged to 24.5 inches

So, 5 * k = 17.5 and 7* k = 24.5

After solving these two equations, we get

k = 3.5

Answer 2

31.5 over 7 because when applying a ratio the second number goes on top and first goes on bottom