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:

6b

Step-by-step explanation:

Answer:

w = 15 (4^t)

Step-by-step explanation:

Let w be what the function is equal to

Let t be the input variable

equation :

w = k a^t

Plug in any two of the points to solve for k and a

for example, let's take (1, 60) and (2, 240):

60 = k * a^1

k = 60 / a

240 = k a^2

Substituting:

240 = 60/a (a^2)

a = 4

k = 15

The function is

w = 15 (4^t)

Answer:

xy

Step-by-step explanation:

The HCF is known as the highest common factor. To find the HCF of two values, we have to take the greatest number that fits into all of their factors.

To start, we can list each value's factors.

For 4x²y, this can also be written as 4*x²*y = 4*x*x*y. In multiplication, we can take the factors of each value that is multiplied. Therefore, we can start with the factors of 4 and then go to the factors of x² and so on. Our factor list is thus 1,2,4,x,x²,y

Similarly, for xy² = x*y*y, our factors are x, y, and y²

The common factors for each of these are x and y. Assuming all values are positive and greater than 1, the x*y will be greater than either x or y. Therefore, the highest common factor would be x*y = xy

Answer:

We know that Sin,

 [tex]=\frac{perpendicular}{hypotenuse}[/tex]

[tex]SinA=\frac{BC}{AC}[/tex]

[tex]SinA=\frac{9}{41}[/tex]

OAmalOHopeO

Answer:

Step-by-step explanation:

It is a positive, or upwards-opening, quadratic; this implies it is parabolic in shape. It has 2 real zeros of x = 5 and x = 1, a y-intercept of (0, 5), and a vertex located at (3, -4). Not sure what else you can possibly need to know about this parabola.

Answer:

Y =  -1/2X +4

Step-by-step explanation:

x1 y1  x2 y2

2 3  0 4

(Y2-Y1) (4)-(3)=   1  ΔY 1

(X2-X1) (0)-(2)=    -2  ΔX -2

slope= -  1/2    

B= 4          

Y =-0.5X +4    

Answer:

Step-by-step explanation:

Eight flapjacks

2oz of butter

3oz of sugar

4 oz of rolled oats.

Each flapjack

Butter = 2/8 = 1/4 oz

Sugar = 3/8 oz

Rolled oats = 4/8 = 1/2 oz

How many flapjacks can I make if I have

14 oz of butter,

15 oz of sugar, and

16 oz of rolled oats?

Butter

= 14 oz ÷ 1/8 oz

= 14 × 8/1

= 112 flapjack

Sugar

= 15 oz ÷ 3/8 oz

= 15 × 8/3

= 120/3

= 40 flapjacks

Rolled oats

16 oz ÷ 1/2 oz

= 16 × 2/1

= 32 flapjack

Therefore,

Considering the quantity of rolled oats available, the number of flapjacks that could be made is 32

Answer:

11.31 units

Step-by-step explanation:

a^2 + b^2 = c^2

8^2 + 8^2 = c^2

64 + 64 = c^2

128 = c^2

Opposite of exponents is square roots, and we need to get rid of that exponent in c^2, meaning we find the square root.

[tex]\sqrt{128\\} \\\\[/tex] = c

c = 11.31 units

Answer:

A

Step-by-step explanation:

Equate f(x) to 8 , that is

[tex]2^{x}[/tex] = 8 = 2³

Since bases on both sides are equal, both 2, then equate exponents

x = 3

The value of the x when the exponential function shown in the graph f(x) = 2ˣ is 8 is when x = 3, which is option A.

Here, given the graph of the function,

f(x) = 2ˣ

We have to find the value of x when f(x) = 8.

In order to find the value of x, when f(x) = 8, we have to write as,

f(x) = 8

2ˣ = 8

Now write 8 as an exponent with base 2.

2ˣ = 2³

Hence the value of x = 3

Learn more about Exponential Functions here :

https://brainly.com/question/9919887

#SPJ7

Answer:

36 pi m^2

Step-by-step explanation:

The diameter of a circle is 12

The radius is 1/2 of the diameter, d/2 = 12/2 = 6

The area of a circle is given by

A = pi r^2

A = pi (6)^2

A = 36 pi m^2

The cake has a cylindrical format, and the outside of the cake will be frosted, which means that the total surface area has to be found, and doing this, we find that she will need 298.5 square inches of frosting.

Surface area of a cylinder:  

The surface area of a cylinder of radius r and height h is given by:

[tex]S = 2\pi r^2 + 2\pi rh[/tex]

The cake is 10 inches in  diameter and 4.5 inches tall.

Radius is half the diameter, so [tex]r = \frac{10}{2} = 5[/tex].

The height is [tex]h = 4.5[/tex].

How many square inches of frosting  will she need?

This is the surface area, so:

[tex]S = 2\pi(5)^2 + 2\pi(5)(4.5) = 50\pi + 45\pi = 95\pi = 298.5[/tex]

She will need 298.5 square inches of frosting.

A similar problem can be found at https://brainly.com/question/24332238

Answer:

Step-by-step explanation:

First of all, we need the formula of a cylinder which is: 2[tex]\pi[/tex]rh + 2[tex]\pi[/tex][tex]r^{2}[/tex]

BUT also remember we are solving for one base since we do not count the bottom of the tray. That formula would look like this: 2[tex]\pi[/tex]rh + [tex]\pi[/tex][tex]r^{2}[/tex] since we are using 1 base instead of 2.

Now input the missing values into the formula and solve:

2[tex]\pi[/tex]rh + [tex]\pi[/tex][tex]r^{2}[/tex]

2[tex]\pi[/tex](5)(4.5) + [tex]\pi[/tex][tex](5^{2})[/tex]

45[tex]\pi[/tex] + 25[tex]\pi[/tex] = 70[tex]\pi[/tex]

Our Answer is 70[tex]\pi[/tex], or 219.91 [tex]in^{2}[/tex]

Answer:

Step-by-step explanation:

Find the slope of the line AB.

The slope:

Since the altitude is perpendicular to AB, it has a slope of -2.

The line with the slope of -2 and passes through point C(6, 16).

Use point-slope equation to find the line:

A = 2, B = 1, C = 28

Answer:

Solution given:

A(7,9)

B(11,11)

C(6,16)

Slope of AB=[tex]\frac{11-9}{11-7}=\frac{2}{4}=½[/tex]

since altitude is perpendicular to it .

so its slope becomes negative reciprocal to the slope of base

so

slope of altitude(m) =-2

now

equation of a line passing through C(6,16) perpendicular to its base is:

By using formula

[tex]y-y_{1}=m(x-x_{1})[/tex]

y-16=-2(x-6)

solve it

y-16=-2x+12

y+2x=12+16

in the form of Ax +By=C is:

2x+y=28

:.

B=1

C=28

Answer:

the equation is 2p-7=25 // p = 16

Answer:

Your uncle's backpack weighs 16 pounds.

Step-by-step explanation:

1.) Add 7 to each side

2p=32

2.) Divide each side by 2

p = 16

3.) That is your answer.

Answer:

b

Step-by-step explanation:

when raising a fraction to a power both the numerator and denominator has to be raised to that power

Answer:

KL = 18

Step-by-step explanation:

The midsegment TU is half the sum of the parallel bases , that is

[tex]\frac{KL+JM}{2}[/tex] = TU

[tex]\frac{KL+34}{2}[/tex] = 26 ( multiply both sides by 2 )

KL + 34 = 52 ( subtract 34 from both sides )

KL = 18

Answer:

plant B

Consistent means better so plant be had more better yields

Answer:

Disagree. As long as the odd number (7) is multiplied by an even number, the sum of multiples of an odd and even number in general will add to be even.

Step-by-step explanation:

Assume you have a=7 and b=8.

Now there are 4 combinations since there are only two types of numbers: even and odd.

Combination 1 would consist of an ODD amount of multiples of a, and and ODD amount of multiples of b.

     See:  3a + 3b

              3(7) + 3(8) = 45

*Combination 2 would be an EVEN amount of a and an EVEN amount of b.

         2a + 2b

         14 + 16 = 30

HERE, in combination 2, the claim is already debunked.

Combination 3 is an ODD amount of a and an EVEN amount of b

         1a + 2b

        7 + 16 = 21

*Combination 4 is an EVEN amount of a and an ODD amount of b

         2a + 1b

         14 + 8 = 24

HERE, in combination 4, the claim is justified again

Answer:

3/5

Step-by-step explanation:

Cos C = adjacent/hypotenuse

or, Cos C = 21/35 = 3/4

Answered by GAUTHMATH

Answer: x>12

so i think x is 16.

Answer:

[tex]y = - \frac{3}{2} x + 1[/tex]

Step-by-step explanation:

Slope -intercept form: y= mx +c, where m is the slope and c is the y-intercept.

Parallel lines have the same slope. Let's find the slope of the given line.

Given points: (-2, 0) and (0, -3)

[tex]\boxed{slope = \frac{y1 - y2}{x1 - x2} }[/tex]

slope of given line

[tex] = \frac{0 - ( - 3)}{ - 2 - 0} [/tex]

[tex] = \frac{0 + 3}{ - 2} [/tex]

[tex] = - \frac{3}{2} [/tex]

[tex]y = - \frac{3}{2} x + c[/tex]

Given that the y- intercept is 1, c= 1.

[tex]y = - \frac{3}{2} x + 1[/tex]

Answer:

Size of the original rectangle is 30*20=600

Step-by-step explanation:

Let the length and width of rectangle be x+10 and x. After increasing the dimensions, the new length and width are x+20 and x+10

ATQ, (x+20)(x+10)=2(x+10)(x), x=20.

Answer:

0.305

Step-by-step explanation:

We are told that area under the standard normal curve to the right of z = -0.51 is 0.6950

Thus, to get the area to the left, we just subtract 0.6950 from 1.

Thus;

area to the left of z = 0.51 is;

P( z < 0.51) = 1 - 0.6950 = 0.305

Answer:

Solution given

Cos[tex]\displaystyle \theta_{1}=\frac{13}{15}[/tex]

consider Pythagorean theorem

[tex]\bold{Sin²\theta+Cos²\theta=1}[/tex]

Subtracting [tex]Cos²\theta[/tex]both side

[tex]\displaystyle Sin²\theta=1-Cos²\theta[/tex]

doing square root on both side we get

[tex]Sin\theta=\sqrt{1-Cos²\theta}[/tex]

Similarly

[tex]Sin\theta_{1}=\sqrt{1-Cos²\theta_{1}}[/tex]

Substituting value of [tex]Cos\theta_{1}[/tex]

we get

[tex]Sin\theta_{1}=\sqrt{1-(\frac{-13}{15})²}[/tex]

Solving numerical

[tex]Sin\theta_{1}=\sqrt{1-(\frac{169}{225})}[/tex]

[tex]Sin\theta_{1}=\sqrt{\frac{56}{225}}[/tex]

[tex]Sin\theta_{1}=\frac{\sqrt{56}}{\sqrt{225}}[/tex]

[tex]Sin\theta_{1}=\frac{\sqrt{2*2*14}}{\sqrt{15*15}}[/tex]

[tex]Sin\theta_{1}=\frac{2\sqrt{14}}{15}[/tex]

Since

In III quadrant sin angle is negative

Answer:

Step-by-step explanation:

In the quadrant III both the sine and cosine get negative value.

Use the identity:

And consider negative value as mentioned above:

Answer:

Let m = Number of months

Company A: 60+ 42.95 m

Company B: 25+49.95 m

60+ 42.95 m= 25+49.95 m

Subtract 42.95 from both sides

60 = 25 + 7m

Subtract 25 from both sides

35= 7m

Divide both sides by 7

m = 5

OAmalOHopeO

Answer:

Is this a trick question ???

Why would the ratio of salt to pepper change if you doubled the recipe?

The amount of salt and pepper would double, but not the ratio...

the answer should be 2:3

Step-by-step explanation:

Answer:

a

Step-by-step explanation:

i took this and got a 100

Answer:

y = 9x

Step-by-step explanation:

other person is so wrong, hope this helps.

Answer:

4/5 or 0.8

Step-by-step explanation:

this problem description is not very precise. it leaves out the definition what corners or sides of JKLM correspond to corners and sides of ABCD.

I assume J and K correlate to A and B, and JK is a long side of JKLM.

so, we are going from JKLM to ABCD.

that means we are going from larger to smaller (as JK = 15 and therefore larger than AB = 12).

what is the scale factor to go from 15 to 12 ?

15 × x = 12

x = 12/15 = 4/5 or 0.8