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3 years ago

What is the length of DC? In this diagram, ΔABC ~ ΔEDC.

Mathematics

1 answer:

Grace [21]3 years ago

7 0

Answer:
<span>D) 5
</span>
Explanation:
Since the two triangles are similar:
therefore:
AC/CE = BC/CD
We are given that:
AC = 21
CE = 7
BC = 20-x
CD = x
Substitute with the givens in the above relation and solve for x as follows:
AC/CE = BC/CD
21/7 = (20-x) / x
3 = (20-x)/x
3x = 20-x
3x+x = 20
4x = 20
x = 20/4
x = 5
Now we have:
BC = 20-x = 20-5 = 15
CD = x = 5

Hope this helps :)

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Are the equations – 2x = 10 and -5x = 25 equivalent? Explain

Dahasolnce [82]

Answer:NO

Step-by-step explanation:

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4 years ago

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Nadia is a stockbroker. She earns 13% commission each week. Last week, she sold $4,500 worth of stocks. How much did she make

m_a_m_a [10]

Multiply amount sold by commission rate:

4500 x 0.13 = 585

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585 x 52 = 30,420

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3 years ago

Is a triangle with sides of length 6ft, 21 ft, 23 ft. A right triangle?

gayaneshka [121]

Answer:

Step-by-step explanation:

By using the Pythagoras theorem, it can be easily determined that whether the triangle is right triangle or not.

Thus, $a^{2}+b^{2}=c^{2}$ where where a and b are the legs and c is the hypotenuse.

Let a=6ft, b=21ft and c=23ft, then

$a^{2}+b^{2}=c^{2}$

$(6)^{2}+(21)^{2}=(23)^{2}$

$36+441=(23)^{2}$

$477=529$

which is not possible, therefore the given triangle is not right triangle because it does not satisfy the Pythagoras theorem.

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3 years ago

There are 30 students in a classroom. The ratio of boys to girls is 2:3.

Arisa [49]

<h3>♫ - - - - - - - - - - - - - - - ~Hello There!~ - - - - - - - - - - - - - - - ♫</h3>

➷ Split 30 into the ratio 2 : 3

12 : 18

12 / 18 + x = 1/5

Cross multiply:

12(5) = 1(18 + x)

60 = 18 + x

Subtract 18 from both sides:

x = 42

42 girls entered the classroom

➶ Hope This Helps You!

➶ Good Luck (:

➶ Have A Great Day ^-^

↬ ʜᴀɴɴᴀʜ ♡

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3 years ago

in parallelogram ABCD, AB=(6x-2) feet DC=(3x+13) feet and AD=5 feet. Find the number of feet in the perimeter of the parallelogr

sweet [91]

Answer:

66 feet

Step-by-step explanation:

Parallelograms have 2 pair of parallel sides that are congruent to each other.

In parallelogram ABCD, we can say:

AB = DC

and

BC = AD

AB and DC are given, and they are equal. So we can say:

AB = DC

6x - 2 = 3x + 13

Now we can solve for x:

6x - 2 = 3x + 13

6x - 3x = 13 + 2

3x = 15

x = 15/3

x = 5

So,

AB = 6x - 2

AB = 6(5) - 2 = 28

So, DC = 28

We are also given AD = 5, so BC = 5 as well [since AD = BC]

Now, we know the length of all 4 sides.

The perimeter is the sum of all 4 sides. Hence,

Perimeter = 28 + 28 + 5 + 5 = 66 feet

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4 years ago