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Eden loves photography. She took a picture of a waterfall that she would like to print and frame to give to her grandmother as a present. She is going to print the photo out as a 5x7 (5 inches wide by 7 inches long) and would like to get a frame to fit it but she doesn’t want the width of the frame to exceed ½ inch. Eden found a frame online that she thinks would be perfect but the description doesn’t mention the width of the frame, only that the total area of the frame and included picture is 63 in2. Determine the width of the frame and if it will work for Eden. Include a sketch.

2 Answers

5 votes
To solve this problem, we can use the formula for the area of a rectangle, which is:

A = lw

where A is the area, l is the length, and w is the width. We are given that the photo is 5 inches wide by 7 inches long, so the area of the photo is:

A_photo = lw = (5 in)(7 in) = 35 in^2

We are also given that the total area of the frame and included picture is 63 in^2. Let's call the width of the frame x. Then the length of the frame must be:

l_frame = 7 in + 2x

since there are two widths of the frame that add to the length of the photo. The width of the frame must be:

w_frame = 5 in + 2x

since there are two widths of the frame that add to the width of the photo. The area of the frame and included picture is:

A_frame = l_frame * w_frame = (7 in + 2x)(5 in + 2x)

We are given that the total area is 63 in^2, so we can set up the equation:

A_frame = A_photo + 63 in^2

(7 in + 2x)(5 in + 2x) = 35 in^2 + 63 in^2

Expanding the left side of the equation, we get:

35 in^2 + 24x + 4x^2 = 98 in^2

Subtracting 98 in^2 from both sides, we get:

24x + 4x^2 = 63 in^2 - 35 in^2 = 28 in^2

Simplifying, we get:

4x^2 + 24x - 28 = 0

Dividing both sides by 4, we get:

x^2 + 6x - 7 = 0

We can factor this equation as:

(x + 7)(x - 1) = 0

This gives us two possible solutions:

x = -7 or x = 1

Since the width of the frame cannot be negative, the only possible solution is x = 1. Therefore, the width of the frame is 1/2 inch, which is less than the maximum width that Eden wants. The frame will work for Eden.

Sketch:

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User Lostaman
by
7.7k points
5 votes

Answer:

Area of a rectangle.

Total area of the frame: 63in²

Length: 7in

Width: ?

  • A = l × w

63 = 7 × w

7 × w = 63

w = 63 ÷ 7

w = 9

So no, the frame won't fit for her photograph as the frame is 4 inches wider than preferred.

User Aei
by
8.6k points