1^2 +2^2+••••+n^2=1/6n(n+1)(2n+1)
using maths induction ​

Answer:

u^2- 18u +81 = (u-9)^2

Step-by-step explanation:

u^2- 18u +

Take the u coefficient

-18

Divide by 2

-18/2 = -9

Square it

(-9)^2 = 81

u^2- 18u +81 = (u-9)^2

Answer:

The blank should contain 81

Step-by-step explanation:

E = u^2 - 18u + (-18/2)^2

E = (u^2 - 18u + 9^2)

E = (u - 9)^2

To be perfectly correct what you have there is a perfect square, but you need to subtract out (9/2)^2 to make it a valid statement.

E = (u - 9)^2 - 81

Answer:

0.6 = 60% probability that a randomly selected application from this distribution took less than 18 minutes.

Step-by-step explanation:

Uniform probability distribution:

An uniform distribution has two bounds, a and b.  

The probability of finding a value of at lower than x is:

[tex]P(X < x) = \frac{x - a}{b - a}[/tex]

The probability of finding a value between c and d is:

[tex]P(c \leq X \leq d) = \frac{d - c}{b - a}[/tex]

The probability of finding a value above x is:

[tex]P(X > x) = \frac{b - x}{b - a}[/tex]

Uniform distribution between 15 and 20 minutes.

This means that [tex]a = 15, b = 20[/tex]

What is the probability that a randomly selected application from this distribution took less than 18 minutes?

[tex]P(X < 18) = \frac{18 - 15}{20 - 15} = 0.6[/tex]

0.6 = 60% probability that a randomly selected application from this distribution took less than 18 minutes.

Answer:

24 + 30 = 54 pancakes flipped in 2 minutes :)

Step-by-step explanation:

damon = 5 pancakes in 20 seconds

we do 20 x 3 and 5 x 3 to find how many pancakes he can flip in a minute

15 pancakes and a minute, we then multiply them by 2 to get the amount for 2 minutes

30 pancakes flipped in 2 minutes

Hailey = 2 pancakes in 10 seconds. to make it an equal amount of pancakes per second with damon, i will multiply them by 2 to have 4 pancakes in 20 seconds

we will then do 4 x 3 and 20 x 3 to find out how many pancakes per minute

then we multiply by 2 for 2 minutes

Answer:

54

Step-by-step explanation:

2 minutes=120 seconds

Damon=120 divide 20=6

6x5=30

Hailey=120 divide 10=12

12x2=24

24+30=54

Hope this helps! Thanks.

Answer:

Step-by-step explanation:

Using the theorem of the middle in a triangle:

[tex]2x+22=\dfrac{x+20}{2} \\\\4x+44=x+20\ cross\ products\\\\3x=-24\\\\x=-8\\[/tex]

Step-by-step explanation:

volume of sphere = 288

based on formula, V = 4/3πr³

288 = 4/3(3.14)r³

288 = 4.187(r³)

r³ = 288/4.187

r =

[tex] \sqrt[3]{68.78} [/tex]

r = 4.09

= 4.1

Answer:

-78

Step-by-step explanation:

Zinc group :

Mean, x1 = 3328

σ1 = 640

Sample size, n1 = 28

Placebo group :

Mean, x2 = 3406

σ2 = 851

Sample size, n2 = 31

The point estimate for the true difference between the population means is obtained as :

Mean difference between population :

x1 - x2 = 3328 - 3406 = - 78

Answer:

6

Step-by-step explanation:

21-20 = 1

20-18 =2

18 -15 = 3

15-11 = 4

We are subtracting 1 more each time

11-5 = 6

Answer:

C: 70 Mins

Step-by-step explanation:

1, 20ft*15ft=300ft^2

2, 30ft*25ft=750ft^2

3, 750ft-350ft=450ft^2

4, 450 ft^2 = 30 mins

5, 350ft=750ft=1050ft^2

6, 1050/450=2.3333

7, 30*2.3333=70

8, 70 mins

At the same rate per square foot , Bert will take 80 minutes to mow the both lawns.

Rate is the ratio between two related quantities in different units.

Area of the rectangular lawn = lw

where

area of the lawn1  = 30 × 25 = 750 ft²

area of the lawn2 = 20 × 15 = 300 ft²

Therefore,

He mow the firts lawn 30 minutes longer than the second lawn. Therefore,

let

x = time to mow the second lawn

x + 30 = time to mow the first lawn

rate for the first lawn = 30 + x / 750

rate for the second lawn = x / 300

Hence,

30 + x / 750 = x / 300

cross multiply

9000 + 300x = 750x

9000 = 750x - 300x

9000 =  450x

x = 9000 / 450

x = 20

it will take him 30 + 20 + 20 = 80 minutes to mow the both lawns.

learn more on rate here: https://brainly.com/question/5219196

Answer:

Destiny will be able to create 12 identical snack bags.

Step-by-step explanation:

Given that a snack bag will be 1 chocolate candy bar, and 1 cookie, we have to subtract 1 chocolate for every cookie she has, and that will leave us with 6 chocolate bars left. The equation for this is 18 - 12 = 6.

Answer:

g+b

number of girls+number of boys

if i am incorrect forgive me plz

The expression for the total number of children in a room is g+ b.

Expressions in math are mathematical statements that have a minimum of two terms containing numbers or variables, or both, connected by an operator in between.

Addition is the process of finding the total, or sum, by combining two or more numbers or variables.

According to the given question

We have

Number of girls = g

And, number of boys = b

Therefore, the expression for the total number of children in room is given by

Total number of children = g + b

Hence, the expression for the total number of children in a room is g+ b.

Learn more about expression and addition here:

https://brainly.com/question/10386370

#SPJ2

Answer:

same line infinite solutions

Step-by-step explanation:

5x − 6y = 4

10x − 12y = 8

10x − 12y = 8

10x − 12y = 8

0 = 0

same line infinite solutions

Answer:

Cantor's intersection theorem refers to two closely related theorems in general topology and real analysis, named after Georg Cantor, about intersections of decreasing nested sequences of non-empty compact sets.

Answer:

45

Step-by-step explanation:

because 5•9=45 so yeah that's the answer

Using Pythagorean Theorem

[tex]\\ \sf\longmapsto H^2=P^2+B^2[/tex]

[tex]\\ \sf\longmapsto H^2=8^2+15^2[/tex]

[tex]\\ \sf\longmapsto H^2=64+225[/tex]

[tex]\\ \sf\longmapsto H^2=289[/tex]

[tex]\\ \sf\longmapsto H=\sqrt{289}[/tex]

[tex]\\ \sf\longmapsto H=17[/tex]

Based on the fact that you asked this three times and got the same answer three times, I suspect the interpretation made by the users that posted those answers was incorrect, and that you meant to ask about dividing in base 2.

We have

111001₂ = 1×2⁵ + 1×2⁴ + 1×2³ + 1×2⁰ = 57

1101₂ = 1×2³ + 1×2² + 1×2⁰ = 13

and 57/13 = (4×13 + 5)/13 = 4 + 5/13.

4 = 2² is already a power of 2, so we have

111001₂/1101₂ = 1×2² + 5/13

we just need to convert 5/13. To do this, we look for consecutive negative powers of 2 that 5/13 falls between, then expand 5/13 as the sum of the smaller power of 2 and some remainder term. For instance,

• 1/4 < 5/13 < 1/2, and

5/13 - 1/4 = (20 - 13)/52= 7/52

so that

5/13 = 1/4 + 7/52

or

5/13 = 1×2 ⁻² + 7/52

Then a partial conversion into base 2 gives us

111001₂/1101₂ = 1×2² + 1×2 ⁻² + 7/52

111001₂/1101₂ = 100.01₂ + 7/52

Continuing in this fashion, we find

• 1/8 < 7/52 < 1/4, and

7/52 = 1/8 + 1/104

==>   111001₂/1101₂ = 100.011₂ + 1/104

• 1/128 < 1/104 < 1/64, and

1/104 = 1/128 + 3/1664

==>   111001₂/1101₂ = 100.0110001₂ + 3/1664

• 1/1024 < 3/1664 < 1/512, and

3/1664 = 1/1024 + 11/13312

==>   111001₂/1101₂ = 100.0110001001₂ + 11/13312

• 1/2048 < 11/13312 < 1/1024, and

11/13312 = 1/2048 + 9/26624

==>   111001₂/1101₂ = 100.01100010011₂ + 9/26624

• 1/4096 < 9/26624 < 1/2048, and

9/26624 = 1/4096 + 5/53248

==>   111001₂/1101₂ = 100.011000100111₂ + 5/53248

and so on.

It turns out that this pattern repeats, so that

[tex]\displaystyle \frac{111001_2}{1101_2} = 100.\overline{011000100111}_2[/tex]

Answer:

6.22 sec

Step-by-step explanation:

h(t) = 105t-16t^2

For values of t for which height will be 34 feet can be obtained by substituting 34 in place of h(t) and solving for t

34=105t-16t^2, using quadratic formula we have t=1/32*(105±sqrt(8849)) which translates to - 0.34sec and 6.22sec but as time can't be negative, time is 6.22sec

Answer:

4/3

Step-by-step explanation:

just do the lcm of denomination and after that start solving

9514 1404 393

Answer:

  1 23/24

Step-by-step explanation:

Fractions can be added when they have the same denominator. Then the addition is performed by adding the numerators, and expressing the sum over the common denominator.

Here, your fractions have denominators of 8 and 6. Usually, we want to find a "least common denominator" to use to express the fractions. There are various ways to find that value. One of the easiest is to consult your memory of multiplication tables to find the smallest number that both a multiple of 8 and a multiple of 6. That number is 24.

An equivalent fraction is one that has the same value, but a different denominator than the one it is being compared to. Equivalent fractions can be made by multiplying by "1" in the form of "a/a" where "a" is any non-zero value. Here, it is useful to multiply 9/8 by 3/3 to make the equivalent fraction 27/24, which has a denominator of 24.

Similarly, we can multiply 5/6 by 4/4 to get the equivalent 20/24, which also has a denominator of 24.

These two fractions can now be added:

  [tex]\dfrac{9}{8}+\dfrac{5}{6}=\dfrac{27}{24}+\dfrac{20}{24}=\dfrac{27+20}{24}=\dfrac{47}{24}[/tex]

If you want to turn this into a "mixed number", you need to find how many times 24 goes into 47: 47÷24 = 1 remainder 23. The quotient is the integer part of the mixed number; the remainder is the numerator of the fractional part. Then the mixed number value of the sum is ...

  [tex]\dfrac{47}{24}=1\dfrac{23}{24}[/tex]

_____

Additional comments

The product of the denominators can always serve as a common denominator. That may not be the "least" common denominator. If you use that here, you would have ...

  [tex]\dfrac{9}{8}+\dfrac{5}{6}=\left(\dfrac{9}{8}\cdot\dfrac{6}{6}\right)+\left(\dfrac{5}{6}\cdot\dfrac{8}{8}\right)=\dfrac{54+40}{48}=\dfrac{94}{48}[/tex]

This result can be reduced by removing a factor of 2 from numerator and denominator to give 47/24, the sum we had above.

The "least common denominator" (LCD) is the Least Common Multiple (LCM) of the denominators. It can be found by forming the product of the unique factors of the denominators. Here, we have 8 = 2·2·2 and 6 = 2·3. The LCD is the product 2·2·2·3. We recognize that 2³ and 3 are unique factors that need to contribute to the LCD. 2 is subsumed by 2³.

As you can see from the factoring, 2 is a common factor of both numbers. Another way to find the LCD (or LCM of the denominators) is to form their product (8×6 = 48) and divide that by the greatest common factor (GCF), which is 2. (48/2 = 24, the LCD) Sometimes it is easier to find the GCF and compute (product/GCF) than to find the LCM using factoring.

__

If you don't mind the possibility of having to reduce the resulting fraction, the sum of fractions can always be computed as ...

  [tex]\dfrac{a}{b}+\dfrac{c}{d}=\dfrac{ad+bc}{bd}[/tex]

This formula computes 94/48 as the sum of these fractions, effectively leaving out the middle step (9/8×6/6 +...) shown in the work above. I find this especially useful for adding rational expressions, not just numerical fractions.

Answer:

What three consecutive integers have a sum of 87? Which means that the first number is 28, the second number is 28 + 1 and the third number is 28 + 2. Therefore, three consecutive integers that add up to 87 are 28, 29, and 30. We know our answer is correct because 28 + 29 + 30 equals 87 as displayed above.

Step-by-step explanation:

Consecutive integers are as simple as 1, 2, 3!  

Integers are consecutive if one follows another.  How do we "jump" from one integer to the next?  We add 1, right?  7, 8 and 9 are three consecutive integers.  Add one to 7 to get 8 and add one more to get 9.

Now lets think about this in algebraic terms.  Lets name these consecutive integers , x, y and z.  

The problem tells us that their sum is -87.  (Recall, "sum" is just a fancy word for the answer when we add.)

x+y+z = -87  

Here is the trick!  We need to rewrite this equation so that we have only one variable.  Easy!

y is one more that x, so y= x+1

And z is one more than y, so z= y+1.  But y is also equal to (x+1)!  So z=y+1=(x+1)+1=x+2

Now we have a problem that we can solve!  x+(x+1)+(x+2)=-87.  

Combining term.:  3x+3=-87  

Subtract 3 from both sides of the equation:  3x=84

Divide each side of the equation by 3:  x=28

We have solved for x, but we are not done!  We need to find y and z.  I know you can do this.  Remember y is one more than x and z is one more than y.

Check your work!  Make sure these three consecutive numbers do in fact add up to -87.

Answer:18

Step-by-step explanation:

Answer:

Confidence Interval

Lower Limit = $4,233.3

Upper Limit = $4,766.7

With 95% confidence, the mean profit per customer that SoftBus can expect to obtain is between $4,233.30 and $4,766.7 based on the given sample data.

Step-by-step explanation:

The z-score of 95% = 1.96

             Profit         Mean      Square Root

                          Difference    of MD

P1        $5,000       $500        $250,000

P2         4,500          0              0

P3         4,000       -500         $250,000

Total $13,500                        $500,000

Mean $4,500 ($13,500/3)    $166,667 ($500,000/3)

Standard Deviation = Square root of $166,667 = 408.2

Margin of error = (z-score * standard deviation)/n

= (1.96 * 408.2)/3

= 266.7

= $266.7

Confidence Interval = Sample mean +/- Margin of error

= $4,500 +/- 266.7

Lower Limit = $4,233.3 ($4,500 - $266.7)

Upper Limit = $4,766.7 ($4,500 + $266.7)

Answer:

13200 ft

Step-by-step explanation:

1 mi = 5280 ft

5280 ft x 2.5 = 13200 ft

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Answer:

so 3 people both read their books and watched films.

Step-by-step explanation:

n(U) = 50

n(A) = 18 ( read books)

n(B) = 28 ( watched films)

n(A U B) with a line at the top = 7

so

Finding n(AUB)

n( A U B) with a line at the top = n(A) + n(B) - n( A n B)

7 = 50-n(A U B)

or, n( A U B) = 50 - 7

so, n(A U B) = 43

Then

n( A U B) = n(A)+n(B)-n(A n B)

43 = 18 + 28 - n( A n B)

or, 43 = 46 - n(A n B)

or, n(A n B) = 46 - 43

so, n(A n B) = 3

This differential equation is separable:

(1 + y²) dx + (1 + x²) dy = 0

(1 + y²) dx = - (1 + x²) dy

dy/(1 + y²) = -dx/(1 + x²)

Integrating both sides gives

arctan(y) = -arctan(x) + C

and solving for y gives (over an appropriate domain)

y = tan(C - arctan(x))

(the domain being -1 ≤ y ≤ 1).

Answer:

A: the standard error of the mean

Step-by-step explanation:

The most frequently used measure to determine how much difference there is between population mean and sample mean is by calculating the standard deviation of the sampling distribution of the mean. This standard deviation is also referred to as the sew Station.

Answer:

y=-\frac{2}{3}\approx -0.666666667

Answer:

[tex]E(x)=1[/tex]

Step-by-step explanation:

From the question we are told that:

Sample mean 1 [tex]\=x_1=$9[/tex]

Sample mean 1 [tex]\=x_2=$8[/tex]

Sample standard deviation 1 [tex]\sigma_1 = $2[/tex]

Sample standard deviation 1 [tex]\sigma_2 = $1[/tex]

Generally the equation for Point estimate is mathematically given by

[tex]E(x)=\=x_1-\=x_2[/tex]

[tex]E(x)=9-8[/tex]

[tex]E(x)=1[/tex]