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2 years ago

Can someone help me?

Mathematics

1 answer:

Oxana [17]2 years ago

3 0

Answer:

Step-by-step explanation:

To start calculating, we first need to make some proof.

Firstly, since AB = AC, we know that ΔABC is isosceles, which means that ∠ABC = ∠ACB.

Now, looking only to ΔBDE and ΔCDF, we can see that they are similar, because the two of its angles are congruent:

∠BED=∠CFD

∠DBE=∠DCF

To make it easier to visualize which are the corresponding vertexes, we can draw them like this:

And we need to remember that BC is 24, so:

BD+CD=24

Since the triangles are similar, their corresponding sides have constant ratio, which we can calculate from the corresponding sides DE and CF:

$r=\frac{CF}{DE} =\frac{7.5}{4.5} =\frac{5}{3}$

This ratio is the same for the other corresponding sides, so we can apply that for BD and CD:

$r=\frac{CD}{BD} =\frac{5}{3}\\
 \frac{BD}{CD}=\frac{3}{5} \\\\
BD=\frac{3}{5} Cd$

Thus, the measure of CF is approximately 13, alternative D.

You might be interested in

A stock can go up, go down, or stay unchanged. How many possibilities are there if you own 3 stocks?

Gala2k [10]

Answer:

There are 27 different possible outcomes.

Step-by-step explanation:

Assuming that you have 3 different stocks:

First, we need to find the number of events and the number of possible outcomes for each event.

Here we can assume that each one of the stocks is a event, and the number of possible outcomes for each one are:

Stock 1: 3 options (up, down, stay)

Stock 2: 3 options (up, down, stay)

Stock 3: 3 options (up, down, stay)

The total number of possible outcomes is equal to the product of the numbers of options for all the events.

Then the total number of possibilities is:

C = 3*3*3 = 27

4 0

2 years ago

Which correctly describes how the graph of the inequality 6y − 3x > 9 is shaded? -Above the solid line

baherus [9]

The statement which correctly describes the shaded region for the inequality is $\fbox{\begin\\\ Above the dashed line\\\end{minispace}}$

Further explanation:

In the question it is given that the inequality is $6y-3x>9$ .

The equation corresponding to the inequality $6y-3x>9$ is $6y-3x=9$ .

The equation $6y-3x=9$ represents a line and the inequality $6y-3x>9$ represents the region which lies either above or below the line $6y-3x=9$ .

Transform the equation $6y-3x=9$ in its slope intercept form as $y=mx+c$ , where $m$ represents the slope of the line and $c$ represents the $y$ -intercept.

$y$ -intercept is the point at which the line intersects the $y$ -axis.

In order to convert the equation $6y-3x=9$ in its slope intercept form add $3x$ to equation $6y-3x=9$ .

$6y-3x+3x=9+3x$

$6y=9+3x$

Now, divide the above equation by $6$ .

$\fbox{\begin\\\math{y=\dfrac{x}{2}+\dfrac{1}{2}}\\\end{minispace}}$

Compare the above final equation with the general form of the slope intercept form $\fbox{\begin\\\math{y=mx+c}\\\end{minispace}}$ .

It is observed that the value of $m$ is $\dfrac{1}{2}$ and the value of $c$ is $\dfrac{3}{2}$ .

This implies that the $y$ -intercept of the line is $\dfrac{3}{2}$ so, it can be said that the line passes through the point $\fbox{\begin\\\ \left(0,\dfrac{3}{2}\right)\\\end{minispace}}$ .

To draw a line we require at least two points through which the line passes so, in order to obtain the other point substitute $0$ for $y$ in $6y=9+3x$ .

$0=9+3x$

$3x=-9$

$\fbox{\begin\\\math{x=-3}\\\end{minispace}}$

This implies that the line passes through the point $\fbox{\begin\\\ (-3,0)\\\end{minispace}}$ .

Now plot the points $(-3,0)$ and $\left(0,\dfrac{3}{2}\right)$ in the Cartesian plane and join the points to obtain the graph of the line $6y-3x=9$ .

Figure $1$ shows the graph of the equation $6y-3x=9$ .

Now to obtain the region of the inequality $6y-3x>9$ consider any point which lies below the line $6y-3x=9$ .

Consider $(0,0)$ to check if it satisfies the inequality $6y-3x>9$ .

Substitute $x=0$ and $y=0$ in $6y-3x>9$ .

$(6\times0)-(3\times0)>9$

$0>9$

The above result obtain is not true as $0$ is not greater than $9$ so, the point $(0,0)$ does not satisfies the inequality $6y-3x>9$ .

Now consider $(-2,2)$ to check if it satisfies the inequality $6y-3x>9$ .

Substitute $x=-2$ and $y=2$ in the inequality $6y-3x>9$ .

$(6\times2)-(3\times(-2))>9$

$12+6>9$

$18>9$

The result obtain is true as $18$ is greater than $9$ so, the point $(-2,2)$ satisfies the inequality $6y-3x>9$ .

The point $(-2,2)$ lies above the line so, the region for the inequality $6y-3x>9$ is the region above the line $6y-3x=9$ .

The region the for the inequality $6y-3x>9$ does not include the points on the line $6y-3x=9$ because in the given inequality the inequality sign used is $>$ .

Figure $2$ shows the region for the inequality $\fbox{\begin\\\math{6y-3x>9}\\\end{minispace}}$ .

Therefore, the statement which correctly describes the shaded region for the inequality is $\fbox{\begin\\\ Above the dashed line\\\end{minispace}}$

Learn more:

A problem to determine the range of a function brainly.com/question/3852778
A problem to determine the vertex of a curve brainly.com/question/1286775
A problem to convert degree into radians brainly.com/question/3161884

Answer details:

Grade: High school

Subject: Mathematics

Chapter: Linear inequality

Keywords: Linear, equality, inequality, linear inequality, region, shaded region, common region, above the dashed line, graph, graph of inequality, slope, intercepts, y-intercept, 6y-3x=9, 6y-3x>9, slope intercept form.

4 0

3 years ago

Read 2 more answers

If the perimeter of a square is 20, find the length of a diagonal

avanturin [10]

Answer:

7.07

Step-by-step explanation:

<h2><u>Length</u></h2>

a square has equal length on each side

hence is the perimeter is 20 it means that :

each side is 20/4 = 5

we can make a diagonal line which create 3 right angled triangles

2 sides of the triangle are 5 , this is the base and the height

to find the length we can make use of the Pythagoras theorem

c^2 = a^2 + b^2

c is the hypotenuse ( the diagonal;)

a and b are the opposite and adjacent

hence :

c^2 = 5 ^2 + 5^2

c^2 = 50

c = $\sqrt{50}$

c = 7.071

to 3sf

<h3><u>diagonal length = 7.07</u></h3>

6 0

3 years ago

Solve for x & y. 30x−42y=−6 and 5x−7y=−1

vladimir1956 [14]

Um.. Both of those equations are the exact same. Divide both sides of the first equation by 6. You get:

$\frac{30x - 42y}{6} = \frac{-6}{6} \\ 5x - 7y = -1$

That is the exact same as the second equation. This system has an infinite number of solutions. 5x - 7y = -1 is a line, so basically every point on that line is a solution to the system.

For example, $x = 0$ and $y = \frac{1}{7}$ would work, but so would $x = 1$ and $y = \frac{6}{7}$

4 0

3 years ago

The equation 7×+1=4×+10 ?

HACTEHA [7]

7x-4x=10-1
3x=9
3/3x=9/3
x=3

5 0

3 years ago

Read 2 more answers