answer this please, this is kahn academy work

Answer:

12 .

Step-by-step explanation:

12

Answer:

Solution given.

centre (h,k):(-6,1)

radius (r)=2

we have

equation of a circle is:

(x-h)²+(y-k)²=r²

(x+6)²+(y-1)²=2²

(x+6)²+(y-1)²=4 is a required equation of a circle.

Answer:

0.125 ?

Step-by-step explanation:

Answer:

that is you my question is wrong for me

Answer:

D. He should survey all the students in all the history classes to make sure he collects enough data.

Step-by-step explanation:

correct on edge 2021

Answer: The Answer Is 54 ft2

Answer:

54

Step-by-step explanation:

A=1/2(b)(h)

Answer:

large = 12

medium = 18

Step-by-step explanation:

L + M = 30 => L = 30-M

4L+3M =102

substitute : L with M

=> 4(30-M)+3M =102

120-4M+3M = 102

- M = 102-120

-M = -18

=========> M = 18, L = 12

Answer:

C   19.2

Step-by-step explanation:

Corresponding parts have the same proportion

x/24 = 20.8/26

multiply both sides by 24

x = 20.8/26 * 24

x = 19.2

Answer:

C

Step-by-step explanation:

Since the triangles are similar then the ratios of corresponding sides are equal, that is

[tex]\frac{AC}{DF}[/tex] = [tex]\frac{AB}{DE}[/tex] , substitute values

[tex]\frac{x}{24}[/tex] = [tex]\frac{20.8}{26}[/tex] ( cross- multiply )

26x = 499.2 ( divide both sides by 26 )

x = 19.2 → C

Answer: D) f(z) = 7 to the power of 2.

Answer:

The formula for the volume of a triangular prism is:

V=(l)(w)(h)

Where l is the length of the triangle, w is the width of the triangle, and h is the height of the prism

The formula for the volume of a prism is V=Bh , where B is the base area and h is the height. The base of the prism is a rectangle. The length of the rectangle is 9 cm and the width is 7 cm.

Please mark as brainliest if answer is right

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Given:

[tex]a_n[/tex] is an arithmetic sequence.

To find:

The value of [tex]\dfrac{1}{a_1a_2}+\dfrac{1}{a_2a_3}+...+\dfrac{1}{a_{39}a_{40}}[/tex].

Solution:

We have,

[tex]\dfrac{1}{a_1a_2}+\dfrac{1}{a_2a_3}+...+\dfrac{1}{a_{39}a_{40}}[/tex]

It can be written as:

[tex]=\dfrac{d}{d}\left[\dfrac{1}{a_1a_2}+\dfrac{1}{a_2a_3}+...+\dfrac{1}{a_{39}a_{40}}\right][/tex]

[tex]=\dfrac{1}{d}\left[\dfrac{d}{a_1a_2}+\dfrac{d}{a_2a_3}+...+\dfrac{d}{a_{39}a_{40}}\right][/tex]

[tex]=\dfrac{1}{d}\left[\dfrac{a_2-a_1}{a_1a_2}+\dfrac{a_3-a_2}{a_2a_3}+...+\dfrac{a_{40}-a_{39}}{a_{39}a_{40}}\right][/tex]

[tex]=\dfrac{1}{d}\left[\dfrac{1}{a_1}-\dfrac{1}{a_2}+\dfrac{1}{a_2}-\dfrac{1}{a_3}+....+\dfrac{1}{a_{39}}-\dfrac{1}{a_{40}}\right][/tex]

[tex]=\dfrac{1}{d}\left[\dfrac{1}{a_1}-\dfrac{1}{a_{40}}\right][/tex]

[tex]=\dfrac{1}{d}\left[\dfrac{a_{40}-a_1}{a_1a_{40}}\right][/tex]

[tex]=\dfrac{1}{d}\left[\dfrac{a_1+(40-1)d-a_1}{a_1a_{40}}\right][/tex]       [tex][\because a_n=a_1+(n-1)d][/tex]

[tex]=\dfrac{1}{d}\left[\dfrac{39d}{a_1a_{40}}\right][/tex]

[tex]=\dfrac{39}{a_1a_{40}}[/tex]

Therefore, the value of given expression is [tex]\dfrac{39}{a_1a_{40}}[/tex].

Answer:

A(an)   altitude    of a prism is a perpendicular segment that joins the planes of the bases. (The height h is the length of one.)

Step-by-step explanation:

AN ALTITUDE -  An altitude of a triangle is a line segment that passes through a vertex and is perpendicular to (i.e. forms a right angle with) the base line (the side opposite the vertex). The expanded base of the altitude is the line that contains the opposing side. The foot of the altitude is the point where the extended base meets the altitude. The area of a triangle can be calculated using altitudes: one half of the product of an altitude's length and its base's length equals the triangle's area. As a result, the longest altitude is perpendicular to the triangle's shortest side. Through trigonometric functions, the heights are also connected to the triangle's sides.

Hence , the answer is an altitude .

Answer:

The stone will hit the water after 3 seconds

Step-by-step explanation:

Given

[tex]y = -5x^2 + 10x +15[/tex]

Required

At what time will the stone enter the water

When the stone enters the water;

[tex]y = 0[/tex]

So, we have:

[tex]-5x^2 + 10x +15 = 0[/tex]

Divide through by -5

[tex]x^2 -2x -3 = 0[/tex]

Expand

[tex]x^2 +x -3x -3 = 0[/tex]

Factorize

[tex]x(x +1) -3(x +1) = 0[/tex]

Factor out x + 1

[tex](x -3) (x +1) = 0[/tex]

Solve for x

[tex]x - 3 = 0\ or\ x + 1 = 0[/tex]

[tex]x = 3\ or\ x = -1[/tex]

x (time) cannot be negative.

So:

[tex]x = 3[/tex]

Answer:

x=19

Step-by-step explanation:

okay so all those angles there are pretty simple. because of the vertical angles theorem, the angles that go across from each other are equal to each other. On a thing like this those intersections are congruent. So knowing this we can assume that (6x+4)=118. so if you solve the basic algebra for that (you can use mathpapa or smt if you really need the work for that) then it comes out as x=19 which you can check.

6x+4=118

subtract 4 from both sides

6x=114

divide by 6 on both sides

x=19

Hope this helps!

Answer:

a is correct ................

Answer:

The percentage of area under a continous probability curve from negative infinity to x.

Step-by-step explanation:

The normalcdf means the normal cumulative density function, it can be accessed from the TI Calculators from the DIST section which also includes the normalcdf, invNorm, tpdf and other distribution functions.

The syntax is as follows :

normalcdf (lower bound, upper bound, mean, standard deviation)

Hence, to Obtian the probability that a value is between a and b, with mean, x and standard deviation, s

The normalcdf is written as normalcdf(a, b, x, s)