c=1/21.22.23+1/22.23.24+................+1/200.201.202

. = là dấu nhân

Answers

Answer 1

It looks like you have to find the value of the sum,

[tex]C = \displaystyle \frac1{21\times22\times23} + \frac1{22\times23\times24} + \cdots + \frac1{200\times201\times202}[/tex]

so that the n-th term in the sum is

[tex]\dfrac1{(21+(n-1))\times(21+n)\times(21+(n+1))} = \dfrac1{(n+20)(n+21)(n+22)}[/tex]

for 1 ≤ n ≤ 180.

We can then write the sum as

[tex]\displaystyle C = \sum_{n=1}^{180} \frac1{(n+20)(n+21)(n+22)}[/tex]

Break up the summand into partial fractions:

[tex]\dfrac1{(n+20)(n+21)(n+22)} = \dfrac a{n+20} + \dfrac b{n+21} + \dfrac c{n+22}[/tex]

Combine the fractions into one with a common denominator and set the numerators equal to one another:

[tex]1 = a(n+21)(n+22) + b(n+20)(n+22) + c(n+20)(n+21)[/tex]

Expand the right side and collect terms with the same power of n :

[tex]1 = a(n^2+43n+462)+b(n^2+42n+440) + c(n^2+41n + 420) \\\\ 1 = (a+b+c)n^2 + (43a+42b+41c)n + 462a+440b+420c[/tex]

Then

a + b + c = 0

43a + 42b + 41c = 0

462a + 440b + 420c = 1

==>   a = 1/2, b = -1, c = 1/2

Now our sum is

[tex]\displaystyle C = \sum_{n=1}^{180} \left(\frac1{2(n+20)}-\frac1{n+21}+\frac1{2(n+22)}\right)[/tex]

which is a telescoping sum. If we write out the first and last few terms, we have

C = 1/(2×21) - 1/22 + 1/(2×23)

… … + 1/(2×22) - 1/23 + 1/(2×24)

… … + 1/(2×23) - 1/24 + 1/(2×25)

… … + 1/(2×24) - 1/25 + 1/(2×26)

… … + … - … + …

… … + 1/(2×198) - 1/199 + 1/(2×200)

… … + 1/(2×199) - 1/200 + 1/(2×201)

… … + 1/(2×200) - 1/201 + 1/(2×202)

Notice the diagonal pattern of underlined and bolded terms that add up to zero (e.g. 1/(2×23) - 1/23 + 1/(2×23) = 1/23 - 1/23 = 0). So, like a telescope, the sum collapses down to a simple sum of just six terms,

C = 1/(2×21) - 1/22 + 1/(2×22) + 1/(2×201) - 1/201 + 1/(2×202)

which we simplify further to

C = 1/42 - 1/44 - 1/402 + 1/404

C = 1,115/1,042,118 ≈ 0.00106994


Related Questions

Qualitative manpower is the most valuable assets of an organization

Answers

Answer:

True

Step-by-step explanation:

Office resources can be defined as all those means, facilities or equipments, including manpower that are utilized in the operation of various office procedures on a daily basis. Thus, office resources comprises means of communication, means of transportation, manpower (workers or employees), furniture, computer, etc.

Basically, the proper and efficient utilization of office resources determine the level of success that would be achieved in any office.

In Business management, office resources are generally grouped into five (5) main categories and these include;

I. Communication.

II. Transportation.

III. Material and office supplies.

IV. Sources of income (finance).

V. Manpower (human resources).

Manpower is also referred to as human resources or office personnels and it can be defined as the total number of people working from the lower hierarchy to top hierarchy of an organization, engaged in various jobs or tasks at different levels.

Basically, manpower is considered to be the most important type of office resources because it is vital for achieving the organizational goal.

This ultimately implies that, the most valuable assets of an organization is its qualitative manpower because it comprises human competence, skills and knowledge.

HURRY PLEASE

1 To join the school swim team, swimmers must be able to swim at least 500 yards without stopping. Let n represent the number of yards a swimmer can swim without stopping. Write an inequality describing which values of n will result in a swimmer making the team.

Answers

Answer:

n = ≥500

Step-by-step explanation:

They must be able to swim 500 yards or more.

The perimeter of a rectangular park is 300 feet. The length of the park is 10 feet longer than the width.
Find the length of the park.
What is the length of the park?
feet=?​

Answers

Answer:

80 ft

Step-by-step explanation:

width = w

length = w+10

Perimeter of a rectangle

P = 2(l+w)

300 = 2(w+10+w)

300 = 2(2w+10)

Divide by 2

300/2 = 2/2(2w+10)

150 = 2w+10

Subtract 10

150-10 = 2w+10-10

140 = 2w

Divide by 2

140/2 = 2w/2

70 = w

l = w+10

l = 70+10

w = 80

Can somebody please help me?

Answers

Answer:

use Pisagor teorem

Step-by-step explanation:

The line which start on the edge and divided other side 64 and 36 be Y and we use Pisagor teorem so Y²=64*36...... y=8*6=48 .................(1)

use other triangle to find hipotenus 48²+36²=x² .... x= 60

Which of the following terms describes the measure indicated by the black
arrow below?
A. Mean
B. Minimum
C. Range
D. Median

Answers

Answer:

mean

Step-by-step explanation:

The mean is the center of a normal distribution

Show that 1.272727... = 1.27 can be expressed in the form , where p and q are integers and q not equal to 0.​

Answers

Answer:

Hello,

Step-by-step explanation:

[tex]1.272727....=1.\overline{27}\\\\=1+\dfrac{27}{99} \\\\=1+\dfrac{3}{11} \\\\=\dfrac{11+3}{11} \\\\=\dfrac{14}{11} \\[/tex]

One other way:

Let say x=1.272727...

100x=127.272727...

x=1.272727...

99x=126

x=126/99

x=14/11

Consider the reflection of parallelogram PQRS across the line of reflection wy

Answers

Answer:

Consider the reflection of the parallelogram PQRS across the line of reflection wy if RR = 14 Then RZ= If SX=5 then = 5

Step-by-step explanation:

PLZZZ HELPPPPP, HAVE 10 MORE QUESTIONS AND NEED TO FINISH IN 5 MINS

Answers

Answer:

2 cups

Step-by-step explanation:

It would be 1/2 times 4, which would be 2 cups of lime juice.

WILL GIVE BRAINLEST!Two machines are printing shirts. The first machine can produce 2.400 shirts in 150 minutes. The second machine can produce 2.400 shirts in 120minutes. If the two work together, how long will it take them to produce 6,480 shirts? If necessary, round your answer to the nearest whole number.

Answers

Step-by-step explanation:

see the answer in attached picture

pls mark me as brainliest pls

Answer:

If two machine works together it takes 180 minute to complete 6480 shirts

Step-by-step explanation:

2400 ÷ 150 = 6

So here,

1st machine produces 20 shirts per minutes

let, x=minutes for shirt's production

Now,

(16+20)x=6480

36x=6480

x=6480/36

Therefor, x=180 minutes

Wich graph is the result of the reflection f(x) =1/4(8)^x across the y axis and then across the x- axis

Answers

Answer:

I assume that the function is:

[tex]f(x) = \frac{1}{4}*8^x[/tex]

Now let's describe the general transformations that we need to use in this problem.

Reflection across the x-axis:

For a general function f(x), a reflection across the x-axis is written as:

g(x) = -f(x)

Reflection across the y-axis:

For a general function f(x), a reflection across the y-axis is written as:

g(x) = f(-x)

Then a reflection across the y-axis, and then a reflection across the x-axis is just:

g(x) = -(f(-x)) = -f(-x)

In this case, we have:

[tex]f(x) = \frac{1}{4}*8^x[/tex]

then:

[tex]g(x) = -f(-x) = -\frac{1}{4}*8^{-x}[/tex]

Now we can graph this, to get the graph you can see below:

Set up the appropriate trigonometric ratio to determine the value of the safety angle.

Answers

Step-by-step explanation:

sin/cos=tan theta.It is the value of the safety angle

A hemispherical tank is filled with water and has a diameter of 16 feet. If water weighs 62.4 pounds per cubic foot, what is the total weight of the water in a full tank, to the nearest pound?

Answers

Answer: 133,827 lb/ft^3

Step-by-step explanation:

V = (4/3) (3.14)(8^3) = 133,827

(100 PTS!!) Match the following vocabulary

Answers

Answer:

Step-by-step explanation:

1. arc length

2. semicircle

3. minor arc

4. arc measure

5. circumference

6. radius

7. diameter

HOPE THIS HELPS

Answer:arc length

2. semicircle

3. minor arc

4. arc measure

5. circumference

6. radius

7. diameter

Step-by-step explanation:

please solve this ASAP. I need this done but I can't figure it out

Answers

Answer:

x = 61

Step-by-step explanation:

Supplementary angles add up to 180 degrees. We can create an equation and solve for x.

(2x + 6) + (x - 9)= 180

~Combine like terms

3x - 3 = 180

~Add 3 to both sides

3x = 183

~Divide 3 to both sides

x = 61

Best of Luck!

LCM of two even number is 220, find their sum​

Answers

Answer:

Two consecutive even terms and LCM = 180

Let’s assume the two terms:

1st term : 2x

2nd term : 2x + 2

There is a rule which states that

If ‘a’ and ‘b’ are two numbers, then their product is equal to the product of their LCM and HCF.

i.e,

a∗b=HCF∗LCM  - (i)

We can logically say that the HCF of any two consecutive even numbers is always equal to ‘2’ provided that the smallest no. is at least ‘2’.

i.e.,

HCF of ‘2x’ and ‘2x + 2’ is ‘2’ - (ii)

Therefore,

from (i) and (ii),

2x∗(2x+2)=  HCF * LCM

2x∗(2x+2)=2∗180  

x∗(2x+2)=180  

2x2+2x−180=0  

Solving the quadratic equation we get,

x=9,−10 (we discard -10 since it is negative)

Therefore, the numbers are

2∗9=18  (1st no.)

2∗9+2=18+2=20  (2nd no.)

Answer :  18,20

Step-by-step explanation:

order the equations by the steepness of the slopes of their graphs from greatest fj least.

Answers

steepest slope: 2x+3
-3x-4
2/3x-5
flattest slope: -1/5x+2

what is the predecessor of -36

Answers

Answer:

-35

Step-by-step explanation

A predecessor is something that came before the current version, and -36 is negative so before -36 is -35

Answer:

the correct answer is -34

Step-by-step explanation:

A predecessor is something that came before the current version.

hope it helps you

From the Rule y = -4x+1 fill in the following table

Answers

Answer:

y: 1, -3, -7, -11, -15

Step-by-step explanation:

Substitute the value of x in the chart for the formula given:

y = -4x + 1

For the first column in the x-row, do the following

y = -4(0) + 1

y = 1

And...

y = -4(1) + 1

y = -3

And so on.

Can u help solve this

Answers

Answer:

2

Step-by-step explanation:

slope = rise/run

rise = difference in y

run = difference in x

slope = (8 - 2)/(3 - 0)

slope = 6/3

slope = 2

Answer:

Slope = 2

Step-by-step explanation:

Use the Slope-Formula to find the slope

m = slope

m = change in y/change in x

m = (y2 - y1)/(x2 - x1)

Points: (0, 2) (3, 8) where the first point is x1 & y1 and the second point is x2 & y2.

m = (8 - 2)/(3 - 0)

m = 6/3

m = 2

The slope will be 2

CAN SOMEONE PLS TELL ME DOMAIN AND RANGE

Answers

Answers:

Domain is (-4, 3]Range is (-5, 5]

=====================================================

Explanation:

The domain is the set of allowed x input values, aka the set of all allowed x coordinates of the points. We see that [tex]-4 < x \le 3[/tex]. It might help to draw vertical lines through the endpoints until you reach the x axis. Note the open hole at x = -4 to indicate we do not include this as part of the domain (hence the lack of "or equal to" for the first inequality sign).

The interval [tex]-4 < x \le 3[/tex] then can be condensed into the shorthand form (-4, 3] which is the domain in interval notation.

It says: x is between -4 and 3. It can't equal -4 but it can equal 3.

So the use of parenthesis versus square brackets tells the reader which endpoint is included or not.

--------------------------------------------------

The range describes all possible y outputs. We see that y = 5 is the largest it gets and y = -5 is the lower bound. It might help to draw horizontal lines through the endpoints until you reach the y axis. The open hole means -5 is not part of the range.

The range as a compound inequality is [tex]-5 < y \le 5[/tex]. This condenses into the shorthand of (-5, 5] which is the range in interval notation.

Verbally, the range is the set of y values such that y is between -5 and 5. It can't equal -5 but it can equal 5.

Answer:

Hello,

Step-by-step explanation:

Domain(f)= ]-4;3]={x€R | -4<x≤3}

Rang(f)=]-5;5]={y€R | -5< y ≤5}

- 100
-V4
L.A.1
ints
3. What is the simplest form of
a. -51
b. 25i
c. -251
d. 5i

Answers

Answer:

- 5i

Step-by-step explanation:

sqrt(-100) / -sqrt(4)

We know that  sqrt(a) / sqrt(b) = sqrt(a/b)

- sqrt(-100/4)

- sqrt(-25)

We know that sqrt(ab) = sqrt(a) sqrt(b)

- sqrt(25) sqrt(-1)

We know sqrt(-1) = i

Taking the principle value of sqrt(25)

- 5i


(

2
,
2
)
(−2,2) under a translation is
(

3
,
5
)
(−3,5). Find the coordinates of the image of the point
(

3
,
1
)
(−3,1) under the same translation.

Answers

Answer:

kslskd बोडलालामसूनिविवल

Geometry, please answer question ASAP

Answers

Answer:

A

Step-by-step explanation:

The inscribed angle IJK is half the measure of its intercepted arc, so

arc IK = 2 × 75° = 150°

The 3 arcs sum to  360° , then

arc IJ = 360° - (150 + 110)° = 360° - 260° = 100° → A

can uh help me in this

Answers

Answer:

Step-by-step explanation:

b) a² - 1 + b(b - 2a) = a² -1 + b*b -  b*2a     {distributive property}

                              =a² - 1 + b² - 2ab

                               = (a² - 2ab + b² ) - 1  

                               = (a - b)² - 1²           {use identity x²-y²= (x+ y)(x -y)}

                               = (a - b + 1)(a -b +1)

b) 15 +8y + y² - 2x - x² = (y² + 8y  + 15) - x² - 2x

                                    =  (y² + 5y + 3y + 15) - x(x + 2)

                                    = [ y(y + 5) + 3(y +5)] - x(x + 2)

                                   = [(y + 5)(y+3) ] - x(x +2)

1. Find(x) + g(x)
4 options to pick from

Answers

It’s either b or c but I would go for b

Find the area of the following composite figure. Assume angles that look like they are a right angle are
right angles.
14 in
14 in
Q
Leave your answer in terms of . For example your answer might to 98 + 107.
square inches
NOTE: Figures are NOT to scale.

Answers

Answer:

7π + 7π + 196 ( could also be 14π + 196)

Step-by-step explanation:

14 is the length of the square. However it is also the diameter of the circle.

If you do diameter x π you will get the circumfrance. Which in this case is 14π. If your trying to find half of the circumfrance you would do 14π ÷ 2 which is 7π.

After finding 7π for one half a circle you do the same for the other and also get 7π

After finding the 2 half circles find the square which is 14 x 14 = 196

196 + 7π + 7π if you don't want bother pi's there it could also be seen as 196+ 14 π

A man was traveling by air is allowed a maximum of 20kg luggages .The man has four bags weighing 3.5kg ,15 kg ,2kg and 1.5kg .Find excess weight of his luggage. 2 . Express the excess weight as a percentage of his maximum weight allowed.

Answers

Answer:

See explanation

Step-by-step explanation:

Maximum weight = 20 kg

Bag 1 = 3.5kg

Bag 2 = 15 kg

Bag 3 = 2kg

Bag 4 = 1.5kg

Total weight of bags = 22 kg

Excess weight of his luggage = Total weight of bags - Maximum weight

= 22 kg - 20 kg

= 2 kg

Express the excess weight as a percentage of his maximum weight allowed = excess weight / maximum weight × 100

= 2/20 × 100

= 0.1 × 100

= 10%

Express the excess weight as a percentage of his maximum weight allowed = 10%

Please help me!!!!!
What are the answers

Answers

Answer:

y=3x

Step-by-step explanation:

The equation of the line is y=3x

Art class has 444 tables. There are 999 pencils at each table.
Ava multiplied 4\times94×94, times, 9 to find the total number of pencils.
Finn multiplied 9\times49×49, times, 4 to find the total number of pencils.
Who is correct?
Choose 1 answer:

Answers

Answer:

Both Ava and Finn are correct

Step-by-step explanation:

There are 4 tables and 9 pencils at each table

4 ( 9) = 36

9 * 4 = 36

Both Ava and Finn are correct

How do I solve this: 12v + 10v + 14 = 80

Answers

Answer:

v = 3

General Formulas and Concepts:

Pre-Algebra  

Equality Properties

Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of Equality

Algebra I

Terms/Coefficients

Step-by-step explanation:

Step 1: Define

Identify

12v + 10v + 14 = 80

Step 2: Solve for v

Combine like terms:                                                                                         22v + 14 = 80[Subtraction Property of Equality] Subtract 14 on both sides:                       22v = 66[Division Property of Equality] Divide 22 on both sides:                               v = 3
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