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bekas [8.4K]
3 years ago
14

The perimeter of a rectangle is 20 cm. The length is 7 cm. What is the area?

Mathematics
1 answer:
Natalka [10]3 years ago
8 0
Hey there!

So we know the perimeter is 20 cm. Let's make our formula for this.

2L + 2W = 20

The formula for the area of a rectangle is L x W. Let's make this into our formula and fill it in as time goes.

L x W

Our Length is measured at 7 cm, so let's fill that into our formulas.

2(7) + 2W = 20
7 * W = x

Let's use some basic algebra to solve for our perimeter.
2(7) + 2W = 20
14 + 2W = 20
2W = 6
W = 3

This means our Width is 3. Now all we have to do is solve for our area since we have our dimensions.

7 x 3 = 21

The area of the rectangle is 21 cm^2.

I  hope this helps!
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Answer:

19. 11

21. 119

Step-by-step explanation:

19.

(-5)² - [4(-3 ∙ 2 + 4)² + 3] + 5 =

= (-5)² - [4(-6 + 4)² + 3] + 5

= (-5)² - [4(-2)² + 3] + 5

= (-5)² - [4(4) + 3] + 5

= (-5)² - [16 + 3] + 5

= 25 - 19 + 5

= 6 + 5

= 11

21.

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= 5 - 8[6 - (3 ∙ 2 - 8 + 2|-5| - 4) - 7 · 2] - 3² · (-2)

= 5 - 8[6 - (3 ∙ 2 - 8 + 2(5) - 4) - 7 · 2] - 3² · (-2)

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= 5 - 8[6 - (-2 + 10 - 4) - 7 · 2] - 3² · (-2)

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= 5 - 8[6 - 4 - 14] - 3² · (-2)

= 5 - 8[2 - 14] - 3² · (-2)

= 5 - 8[-12] - 3² · (-2)

= 5 - (-96) - 9 · (-2)

= 5 + 96 + 18

= 101 + 18

= 119

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2 years ago
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