Câu 2. Cho hình thang cân ABCD (AB // CD, AB CD). Gọi O là giao điểm của AD và BC, E là giao điểm của AC và BD. Chứng minh rằng: | a) Tam giác AOB cân ở O.
b) Các tam giác ABD và BAC bằng nhau. C) EC = ED
d) OE là trung trực của AB và CD.

Answer: the perimeter is 20

Step-by-step explanation:

Distance between C and D

Sqrt (-2-1)^2 + (1- -3)^2=

Sqrt -3^2 + 4^2=

Sqrt 25 = 5

Between D and E

Sqrt(5-2)^2+(0-4)^2=

Sqrt 25 = 5

Between E and F

Sqrt(1-5)^2+(-3-0)^2=

Sqrt 25=5

It is a square

The value of the perimeter of a quadrilateral is, 20 units

The process of combining two or more numbers is called the Addition. The 4 main properties of addition are commutative, associative, distributive, and additive identity.

We have to given that;

Vertices are,

C (- 2, 1), D (2, 4), E (5, 0), and F (1, - 3).

Since, The distance between two points (x₁ , y₁) and (x₂, y₂) is,

⇒ d = √ (x₂ - x₁)² + (y₂ - y₁)²

Hence, We get;

CD = √(- 2 - 2)² + (1 - 4)²

CD = √16 + 9

CD = √25

CD = 5

DE = √( 2 - 5)² + (4 - 0)²

DE = √9 + 16

DE = √25

DE = 5

EF = √(5 - 1)² + (0 + 3)²

EF = √16 + 9

EF = √25

EF = 5

FC = √(- 2 - 1)² + (1 + 3)²

FC = √9 + 16

FC = 5

Thus, The value of the perimeter of a quadrilateral is,

CD + DE + EF + FC

5 + 5 + 5 + 5

20 units

Learn more about the addition visit:

https://brainly.com/question/25421984

#SPJ2

Answer:

1,086,183,741,982,184

Step-by-step explanation:

998^3

 = (1,000)^3 - (2)^3 - 3 · 1,000 · 2 (1000 - 2)

 = 1,000,000,000 - 8 - 6,000 (998)

 = 999,999,992 - 5,988,000

 = 994,011,992

103^3

 = (100 + 3)^3

 = (100)^3 + (3)^3 + 3(100) (3) + (100+3)

 = 1,000,000 + 27 + 900(103)

 = 1,000,027 + 92,700

 = 1,092,727

994,011,992 · 1,092,727

 = 994,011,992 · (1,000,000 + 90,000 + 2,000 + 700 + 20 + 7)

 = (994,011,992 · 1,000,000) + (994,011,992 · 90,000) + (994,011,992 · 2,000) + (994,011,992 · 700) + (994,011,992 · 20) + (994,011,992 · 7)

= 994,011,992,000,000 + 89,461,079,280,000 + 1,988,023,984,000 + 695,808,394,400 + 19,880,239,840 + 6,958,083,944

 = 1,086,183,741,982,184

Answer:

firstly find the gradient given by the equation

m=y2-y1/x2-x1

in this case x1 is -12,x2 is -17, y1 is -8 and y2 is-16

m=-16+8/-17+12

=-8/-5 or1.6

then use the equation

y-y1=m(x-x1)

y+8=1.6(x+12)

y+8=1.6x+19.2

y=1.6x+11.2

I hope this helps and sorry if it's wrong

Answer:

281.25 cm^2

Step-by-step explanation:

Given that,

The scale factor of Two similar triangles = 5:2

Area of the smaller rectangle = 45 cm^2

To find,

The Area of the larger rectangle = ?

Procedure:

As we know, similar triangles have similar ratios of sides. Thus, this can be written in proportion with the sides' ratio to the left while ratio of areas on the right.

(5)^2/(2)^2 = a/45

∵ The area of the larger rectangle = 25/4 * 45

= 281.25 cm^2

Answer:

It is expected that linearization beyond age 20 will be use a function whose slope is monotonously decreasing.

Step-by-step explanation:

The linearization of the data by first order polynomials may be reasonable for the set of values of age between ages from 5 to 15 years, but it is inadequate beyond, since the fourth point, located at [tex](x,y) = (20, 5.5)[/tex], in growing at a lower slope. It is expected that function will be monotonously decreasing and we need to use models alternative to first order polynomials as either second order polynomic models or exponential models.

Answer:

3 a) solution:-

Discount=Rs 1,200

S .P =RS 4,000

M P=?

we know that,

Discount= M.P - S.P

or, Rs 1,200= M.P - Rs 4,000

or, M.P = RS (4,000-1,200 )

M.P = RS 2,800

In no. 3 all we have to make like this .........

Hope it helps

Answer:

Step-by-step explanation:

2)a) M.P =₹ 5000

S.P = ₹4000

Discount amount = M.P - S.P

                            = 5000 - 4000

                            = ₹1000

Discount percent = [tex]\frac{discount \ amount}{M.P}*100[/tex]

                             [tex]= \frac{1000}{5000}*100\\[/tex]

                             = 20%

3)a) Discount = ₹ 1200

S.P = ₹ 4000

M.P = S.P + discount

      = 4000 + 1200

      =  ₹ 5200

4)a ) Discount rate = 15%

S.P= ₹ 4000

[tex]M.P = \frac{100+Discount rate}{100}*S.P\\\\=\frac{115}{100}*4000[/tex]

= ₹ 4600

The degree 3 polynomial with the zeros {1, 4, 2} and a leading coefficient equal to 1 is:

p(x) = x^3 -7x^2 + 14x - 8

We know that for a polynomial of degree n, with a leading coefficient "a" and the zeros {x₁, x₂, ..., xₙ} can be written as:

p(x) = a*(x - x₁)*(x - x₂)*...*(x - xₙ)

Knowing that here we have a polynomial of degree n = 3, with a leading coefficient a = 1, and the zeros {1, 4, 2}

Replacing these in the above form, we get:

p(x) = 1*(x - 1)*(x - 4)*(x - 2)

Now we can expand that to get:

p(x) = (x^2 - x - 4x + 4)*(x - 2) = (x^2 - 5x + 4)*(x - 2)

p(x) = x^3 - 5x^2 + 4x - 2x^2 + 10x - 8

p(x) = x^3 -7x^2 + 14x - 8

If you want to read more about polynomials, you can read:

https://brainly.com/question/11536910

Answer:

5

Step-by-step explanation:

EB is the median so it is the average of the top and bottom lengths

(38 + 6x-6) /2 = 7x-4

Combine like terms

(32+6x)/2 = 7x-4

Multiply by 2

32+6x = 14x-8

Subtract 6x from each side

32+6x-6x = 14x-6x -8

32 = 8x-8

Add 8 to each side

32+8 = 8x-8

40 = 8x

Divide by 8

40/8 = 8x/8

5 =x

Answer:

2.5777

Step-by-step explanation:

The 6 in "2.577681" is greater than 5, so the value increases by 1.

Answer:

a. p(orange) = 5/14

b. p(green) = 3/14

c. p(red) = 1/7  

d. p(brown) = 2/7  

e. p(brown or red) = 3/7

Step-by-step explanation:

1. You have a 14 pencils. Two pencils are red, 5 pencils are orange, 3 pencils are green and 4 pencils are brown.

p(color) = (number of pencils of that color)/(total number of pencils)

p(color) = (number of pencils of that color)/14

a. If a pencil is picked at random, what is the probability that the pencil

will be orange?

p(orange) = 5/14

b. If a pencil is picked at random, what is the probability that the pencil

will be green?

p(green) = 3/14

c. If a pencil is picked at random, what is the probability that the pencil will be red?

p(red) = 2/14 = 1/7

d. If a pencil is picked at random, what is the probability that the pencil

will be brown?

p(brown) = 4/14 = 2/7

e. If a pencil is picked at random, what is the probability that the pencil

will be brown or red?

brown: 4

red: 2

brown or red: 4 + 2

p(brown or red) = 6/14 = 3/7

Let's take any 2 points from the line.

1. (-4,-2)

2. (-2,-7)

[tex]slope \\ = \frac{Δy}{Δx} \\ = \frac{y_{2} - y_1}{x_{2} - x_1} \\ = \frac{ 7 - ( - 2)}{ - 2 - ( - 4)} \\ = \frac{5}{2} \\ = 2 \frac{1}{2} \\ = 2.5[/tex]

Answer:

a₁₉ = 99

Step-by-step explanation:

The nth term of an arithmetic sequence is

[tex]a_{n}[/tex] = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = 9 and d = 5 , then

a₁₉ = 9 + (18 × 5) = 9 + 90 = 99

The nineteenth term of arithmetic c sequence with first term 9 and common difference 5 is 99.

The difference between every two successive terms in a sequence is the same this is known as an arithmetic progression (AP).

The arithmetic progression has wider use in mathematics for example sum of natural numbers.

Natural number = 1,2,3,4,5,6,7,8...

Now it has the same difference between any two consecutive terms d =2-1 = 3-2

Given an AP series

First term(a) = 9

Common difference (d) = 5

The nth term is given by

⇒ a + (n - 1)d

So,

19th term = 9 + (19-1)5

⇒ 99

Hence "The nineteenth term of arithmetic c sequence with first term 9 and common difference 5 is 99".

For more about Arithmetic progression

https://brainly.com/question/20385181

#SPJ2

Answer:

Which angle are you talking about please?

Answer:

there are relationship between sides of two triangle

Step-by-step explanation:

if 2 multiply by 2 and it new form 4 you should multiply 2 to all side of first triangle so this means 1*2 f=2 and b*2=6 b= 3

Bisect means it is in the middle so that the length of each side would be the same.

The bisector is point W

Answer:

90+ 135= 225

Step-by-step explanation:

a can be found with formula (n-2)×180/n, where n is number of sides

a= 135

b=90

Answer:

0.75, 1.25

Step-by-step explanation:

first we bring the line equation into the same format as the parabola equation (y = ...)

3x - y = 1

=>

y = 3x - 1

now we can say for the intersection points both equations must have the same result.

4x² - 1 = 3x - 1

4x² - 3x = 0

x(4x - 3) = 0

there are only 2 possible cases to make this true :

x = 0

and 4x - 3 = 0

4x = 3

x = 3/4 = 0.75

for the y value let's use the easier equation (line) :

y = 3×3/4 - 1 = 9/4 - 4/4 = 5/4 = 1.25

Answer:

(x, y) → (y, -x)

Step-by-step explanation:

The coordinates of the vertices of parallelogram ABCD are; A(2, 5), B(5, 4), C(5, 2), and D(2, 3)

The coordinates of the vertices of parallelogram A'B'C'D' are; A'(5, -2), B'(4, -5), C'(2, -5), and D'(3, -2)

The rule that escribes the transformation of the rotation of parallelogram ABCD to create the image A'B'C'D' is presented, by observation, is therefore;

(x, y) → (y, -x)

The resulting transformation used will be (x, y) -> (y, -x)

Transformation are rules applied to an object to change its orientation

For the given parallelogram, in order to know the rule used, we need the coordinate of the image and preimage

The coordinate of A is (2, 5) while that of A' is (5, -2).

From both coordinates, you can see that the coordinate was switched and the resulting y coordinate negated.

Hence the resulting transformation used will be (x, y) -> (y, -x)

Learn more on transformation here:  https://brainly.com/question/17311824

Answer:

x = y = 104°

Step-by-step explanation:

The sum of the interior angles = 360°

The opposite angles x and y are congruent , that is y = x , then

92 + 60 + x + x = 360

152 + 2x = 360 ( subtract 152 from both sides )

2x = 208 ( divide both sides by 2 )

x = 104

Then

x = y = 104°

Answer: To add or subtract radicals, the indices and what is inside the radical (called the radicand) must be exactly the same. If the indices and radicands are the same, then add or subtract the terms in front of each like radical. If the indices or radicands are not the same, then you can not add or subtract the radicals.

Answer:

combining like terms. if the radicand is the you can combine the radical. this is the same as combining variables as long as the variable is the same if that makes sense

Step-by-step explanation:

so like you can add 7a and 3a because they have the same variable a. you can combined 2 root 2 and 4 root 2 because the radicand is same <3

Answer: Choice D. [tex]\angle A \cong \angle E[/tex]

Explanation: Since AB is parallel to ED, this means the alternate interior angles A and E are congruent as marked below.

Angle A is congruent to angle E by alternate interior angle theorem. Therefore, option D is the correct answer.

Two triangles are similar if the angles are the same size or the corresponding sides are in the same ratio. Either of these conditions will prove two triangles are similar.

Given that, triangle CAB is similar to triangle CED and AB is parallel to ED.

From the given figure, AB=7 miles, DC=16 ft, EC=12 ft and DE=21 ft.

Here, in figure,

∠A ≅ ∠E  (Alternate interior angles)

∠B ≅ ∠D  (Alternate interior angles)

∠ACB ≅ ∠DCE  (Vertically opposite angles are congruent)

Therefore, option D is the correct answer.

To learn more about the similar triangles visit:

https://brainly.com/question/25882965.

#SPJ7

Answer:

6

Step-by-step explanation:

A=5-x^2+2x

Rewriting

A = -x^2 +2x+5

This is a downward opening parabola so the maximum value is at the vertex

Factor out the negative sign out of the first two terms

A = -(x^2 -2x)  +5

Complete the square

-2/2 = -1   -1^2 = 1

Add 1 inside the parentheses  Remember the negative sign out front so -1(1) is really adding -1  so we need to add 1 outside of the parentheses

A = -(x^2-2x+1) +1  +5

A = -(x-1)^2 +6

This is in vertex form

y = a(x-h)^2 +k  where (h,k) is the vertex

The maximum occurs at x=h and the value is k

The maximum is 6

Step-by-step explanation:

here's the answer to your question

Answer:

the answer is 120

Step-by-step explanation:

a trapezoid should measure 360 when all sides are added together

180-125=55

65+55=120

360-120=240

240÷2=120

Answer:

the next 3 numbers in the pattern are 1/27 , 1/81. , and 1/243

Step-by-step explanation:

to go from 9 to 3 you either have to subtract 6 or divide by 3. if you subtract 6 it doesn't match with the numbers. if you divide by 3 it matches. you can multiply 1/9 by 1/3 or divide by 3. it end with the same answer

We have that The Next 3 patterns are

1/27,1/81,1/243

From the Question we are told that

Pattern. 9 ,3 ,1 ,1/3, 1/9

Generally

Using in inductive reasoning the pattern progresses as a function of  dividing by 3

Therefore

The next three number are

[tex]x_1=\frac{1/9}{3}\\\\x_1=1/27[/tex]

[tex]x_2=\frac{1/27}{3}\\\\x_2=1/81[/tex]

[tex]x_3=\frac{1/81}{3}\\\\x_3=1/243[/tex]

Therefore

The Next 3 Numbers are

1/27,1/81,1/243

For more information on this visit

https://brainly.com/question/22923038?referrer=searchResults

Answer:

y=113505(1+0.012)^(x)

y=120481. Answered by Gauthmath

Answer:

x=24 y=33

Step-by-step explanation:

If a diameter or radius is perpendicular to a chord, then it bisects the chord and its arc.