what is 221st number out of 5,6,7,8,9

(3x-2)(3x+ 2)

Multiply each term in one set of parentheses by the other terms:

3x x 3x =9x^2

3x x 2 = 6x

-2 x 3x = -6x

-2 x 2 = -4

Combine to get:

9x^2 + 6x - 6x -4

Combine like terms:

9x^2 - 4

The value of a would be 9.

[tex]\sf{\bold{\blue{\underline{\underline{Given}}}}}[/tex]

[tex]\sf{\bold{\red{\underline{\underline{To\:Find}}}}}[/tex]

[tex]\sf{\bold{\purple{\underline{\underline{Solution}}}}}[/tex]

At first we have to solve the value of (3x-2)(3x+2)

According to the question,

⠀⠀⠀

[tex]\sf{\bold{\green{\underline{\underline{Answer}}}}}[/tex]

Hence,

The value of a is 9

Mean:

E[X] = ∑ x f(x) = 1 × f (1) + 2 × f (2) + 3 × f (3) = 51/43 ≈ 1.186

Variance:

Recall that for a random variable X, its variance is defined as

Var[X] = E[(X - E[X])²] = E[X ²] - E[X]²

Now,

E[X ²] = ∑ x ² f(x) = 1² × f (1) + 2² × f (2) + 3² × f (3) = 69/43

Then

Var[X] = 69/43 - (51/43)² = 366/1849 ≈ 0.198

(each sum is taken over x in the set {1, 2, 3})

Answer:

D. 750(0.75)ˣ

Step-by-step explanation:

Let the new brightness be L'. Since our initial brightness L₀ reduces by 25 %, we have that L' = L₀ - 25% of L₀

L' = L₀ - 0.25L₀

L' = 0.75L₀

Adding the second screen, the new intensity is L" = L' - 25 % of L'  

L" = L' - 0.25 L'

L" = 0.75L'.

Since L' = 0.75L₀,

L" = 0.75L' = 0.75(0.75L₀) = 0.75²L₀

Adding the third screen, the new intensity is L"' = L'' - 25 % of L''  

L'" = L" - 0.25 L"

L"' = 0.75L".

Since L" = 0.75L' = 0.75²L₀

L"' = 0.75L" = 0.75(0.75²L₀) = 0.75³L₀

So, we see a pattern here.

The intensity after x screens is L = (0.75)ˣL₀

Since L₀ = 750 lumens,

L = 750(0.75)ˣ

Answer:

is it going to be 10.5

Step-by-step explanation:

I do not have any explanation

Answer: 0 (zero)

Step-by-step explanation:

Start Learning & start growing! edge2023

*DROPS THE MIC*

Answer:

3/8

Step-by-step explanation:

the total number of possible results is 4×4=16.

out of these 16 only the results

1 2

1 3

1 4

2 2

2 3

3 2

are desired results. these are 6.

so the probability of a desired result is 6/16 = 3/8

Answer:

Dependent Samples t test

Step-by-step explanation:

The dependent samples t test also called the paired t test are employed in statistical analysis when sample measurement in a certain group is to be paired with the sample measurement on the other group. This is possible because the samples used in the two groups are usually the same. Hence, pairing the samples is feasible in this case. This is different from independent t test as the samples in the groups are entirely different and distinct. Hence, giving no chance to match the samples together. In the scenario described above, the same 20 people(samples) formed the same group of measurement.

Answer:

0.0106 = 1.06% probability that 2 or fewer will withdraw

Step-by-step explanation:

For each student, there are only two possible outcomes. Either they withdraw, or they do not. The probability of an student withdrawing is independent of any other student, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

25% of its students withdraw without completing the introductory statistics course.

This means that [tex]p = 0.25[/tex]

Assume that 30 students registered for the course.

This means that [tex]n = 30[/tex]

Compute the probability that 2 or fewer will withdraw:

This is:

[tex]P(X \leq 2) = P(X = 0) + P(X = 1) + P(X = 2)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{30,0}.(0.25)^{0}.(0.75)^{30} = 0.0002[/tex]

[tex]P(X = 1) = C_{30,1}.(0.25)^{1}.(0.75)^{29} = 0.0018[/tex]

[tex]P(X = 2) = C_{30,2}.(0.25)^{2}.(0.75)^{28} = 0.0086[/tex]

[tex]P(X \leq 2) = P(X = 0) + P(X = 1) + P(X = 2) = 0.0002 + 0.0018 + 0.0086 = 0.0106[/tex]

0.0106 = 1.06% probability that 2 or fewer will withdraw

Hello!

[tex]\large\boxed{P = 300m}[/tex]

Use the following formula for the perimeter:

P = 2l + 2w, where:

l = length

w = width

Therefore:

P = 2(90) + 2(60)

Simplify:

P = 180 + 120 = 300 m

Answer:

well how about you use common sense 100 yards long on each side 200 yards then add 5o yards since the the that is how wide it is then add another 50 and you get 300 yards then convert that to meters

Answer:

Jose has 5.2 meters of fabric left.

Step-by-step explanation:

5.6 - 0.4 = 5.2

Answer:

Step-by-step explanation:

Given expressions are,

[tex]p=\frac{\sqrt{10}-\sqrt{5}}{\sqrt{10}+\sqrt{5}}[/tex] and [tex]q=\frac{\sqrt{10}+\sqrt{5}}{\sqrt{10}-\sqrt{5}}[/tex]

Remove the radicals from the denominator from both the expressions.

[tex]p=\frac{\sqrt{10}-\sqrt{5}}{\sqrt{10}+\sqrt{5}} \times \frac{\sqrt{10}-\sqrt{5}}{\sqrt{10}-\sqrt{5}}[/tex]

  [tex]=\frac{(\sqrt{10}-\sqrt{5})^2}{(\sqrt{10})^2-(\sqrt{5})^2}[/tex]

  [tex]=\frac{(\sqrt{10}-\sqrt{5})^2}{5}[/tex]

[tex]\sqrt{p}=\sqrt{\frac{(\sqrt{10}-\sqrt{5})^2}{5}}[/tex]

      [tex]=\frac{\sqrt{10}-\sqrt{5}}{\sqrt{5}}[/tex]

[tex]q=\frac{\sqrt{10}+\sqrt{5}}{\sqrt{10}-\sqrt{5}}[/tex]

  [tex]=\frac{\sqrt{10}+\sqrt{5}}{\sqrt{10}-\sqrt{5}}\times \frac{\sqrt{10}+\sqrt{5}}{\sqrt{10}+\sqrt{5}}[/tex]

  [tex]=\frac{(\sqrt{10}+\sqrt{5})^2}{(\sqrt{10})^2-(\sqrt{5})^2}[/tex]

  [tex]=\frac{(\sqrt{10}+\sqrt{5})^2}{5}[/tex]

[tex]\sqrt{q}=\sqrt{\frac{(\sqrt{10}+\sqrt{5})^2}{5}}[/tex]

     [tex]=\frac{(\sqrt{10}+\sqrt{5})}{\sqrt{5}}[/tex]

[tex]\sqrt{q}-\sqrt{p}-2\sqrt{pq}=\frac{(\sqrt{10}+\sqrt{5})}{\sqrt{5}}-\frac{(\sqrt{10}-\sqrt{5})}{\sqrt{5}}-2(\frac{(\sqrt{10}+\sqrt{5})}{\sqrt{5}})(\frac{(\sqrt{10}-\sqrt{5})}{\sqrt{5}})[/tex]

                           [tex]=\frac{1}{\sqrt{5}}(\sqrt{10}+\sqrt{5}-\sqrt{10}+\sqrt{5})-\frac{2}{5}[(\sqrt{10})^2-(\sqrt{5})^2)][/tex]

                           [tex]=\frac{1}{\sqrt{5}}(2\sqrt{5})-\frac{2}{5}(10-5)[/tex]

                           [tex]=2-2[/tex]

                           [tex]=0[/tex]

Answer:

a) it is a discrete random variable

b) It is a continuous random variable

c) It is not a random variable

d) It is a discrete random variable

e)  It is a discrete random variable

f) It is a continuous random variable

Step-by-step explanation:

Explanation,

Continuous Random Variable  

A continuous variable is one that can take on an uncountable set of values.

It may take any values within an interval.

It can take infinite values within an interval.

They are obtained by measuring rather than counting.

Discrete Random Variable  

These can only take a discrete value and cannot be expressed in the form of decimals.

They are obtained by counting rather than measuring.

a). it is a discrete random variable  ⇒ as a number of people is a discrete count, which takes values such as 0 or 1 or 2.

b). The exact time it takes to evaluate 27+72 ⇒ Since, Time is measured and thus it is a continuous random variable.

c). The gender of college students ⇒ Gender is categorical data. It is neither continuous nor discrete.

d).  The number of hits to a website in a day ⇒ Since the number of people cannot be expressed as decimals, thus it is a discrete random variable

e). The number of bald eagles in a country ⇒ Since the number of people cannot be expressed as decimals, thus it is a discrete random variable

f).  The distance a baseball travels in the air after being hit  ⇒ Distance is measured and thus it is a continuous random variable.

Answer:

10/7 or 1.428571429

Step-by-step explanation:

We know that x-y=0.7

So, now we have the equation 1÷0.7 or 1÷7/10

Meaning, we can multiply by the reciprocal,

And make this equation into 1×10/7= 10/7

Answer:

452.2 cm

Step-by-step explanation:

A = 4πr²

A = 4 (3.14) (6)²

A = 4 (3.14) (36)

A = 452.16

A = 452.2 cm (nearest tenth)

Answer:

[tex]f(x) - g(x) = 2x + 12[/tex]

[tex]m(x) = f(x) - g(x)[/tex] --- True

Step-by-step explanation:

Given

[tex]f(x) = -3x + 5[/tex]

[tex]g(x) = -5x - 7[/tex]

[tex]m(x) = 2x + 12[/tex]

Solving (a): [tex]f(x) - g(x)[/tex]

From the given parameters, we have:

[tex]f(x) = -3x + 5[/tex]

[tex]g(x) = -5x - 7[/tex]

So:

[tex]f(x) - g(x)=-3x+5 + 5x + 7[/tex]

Collect like terms

[tex]f(x) - g(x) = 2x + 12[/tex]

Solving (b) m(x) = f(x) = g(x)?

In (a), we have:

[tex]f(x) - g(x) = 2x + 12[/tex]

And

[tex]m(x) = 2x + 12[/tex] --- given

By comparison:

[tex]m(x) = f(x) - g(x)[/tex]

Answer:

sorting;

greatest = 2,700

least = 2,250

HAVE A NİCE DAY

Step-by-step explanation:

GREETINGS FROM TURKEY ツ

Answer:

Quadratic formula

Step-by-step explanation:

The function is quadratic because it is a parabola. Exponential functions shoot either upwards or downwards rapidly, and it is clearly not linear due to it's curve. It also isn't piecewise because the function never stops or starts irregularly.

Answer:

5040

Step-by-step explanation:

I assume you really mean 7!

you understand what "!" means ?

n! = n×(n-1)×(n-2)×(n-3)×...×3×2×1

so,

7! = 7×6×5×4×3×2×1

now all you need is a calculator.

7! = 5040

Answer:

Train A speed = x + 20

Train B = x

We know the 46 minutes is 23/30 of an hour.

Use D = rt

Take it from it, hope its helped, have a great day!

Answer:

Step-by-step explanation:

As shown in the graph,

A, B, C and D are the vertices of a square, all sides of the square will be equal in measure.

Coordinates of A → (0, 0)

Coordinates of B → (0, m)

Distance between point D and point A = m

Therefore, coordinates of point D → (m, 0)

Now point C will be equally distant from the points B and D.

Coordinates of C → (m, m)

Answer:

z = ±  0.772193214

Step-by-step explanation:

Hence, the critical value for a [tex]88[/tex]% confidence level is [tex]z=1.56[/tex].

What is the standard deviation?

Standard deviation is the degree of dispersion or the scatter of the data points relative to its mean, in descriptive statistics.

It tells how the values are spread across the data sample and it is the measure of the variation of the data points from the mean.

Here given that,

For a confidence level of  [tex]88[/tex]%, find the critical value for a normally distributed variable.

Let us assume that the standard normal distribution having a mean is [tex]0[/tex] and the standard deviation is [tex]1[/tex].

As the significance level is [tex]1[/tex] - confidence interval

Confidence interval is [tex]\frac{80}{100}=0.88[/tex]

i.e., [tex]1-0.88=0.12[/tex]

For the two sided confidence interval the confidence level is [tex]0.44[/tex].

Now, the standard normal probability table the critical value for the  [tex]88[/tex]% confidence level is [tex]1.56[/tex].

Hence, the critical value for a [tex]88[/tex]% confidence level is [tex]z=1.56[/tex].

To know more about the standard deviation

https://brainly.com/question/13905583

#SPJ5

Answer:

2.56% chance of being selected

Step-by-step explanation:

Given

[tex]n = 39[/tex] --- you and 38 others

Required

Chance of you being selected

To do this, we simply calculate the probability using:

[tex]Pr(x) = \frac{n(x)}{n}[/tex]

Where:

[tex]n(x)= 1[/tex] --- i.e you are just 1 person

So:

[tex]Pr(x) = \frac{1}{39}[/tex]

[tex]Pr(x) = 0.0256[/tex]

Express as percentage

[tex]Pr(x) = 2.56\%[/tex]

Answer:

D) y = –5x + 4x^2 + 2

Step-by-step explanation:

You can tell by the first number being positive or negative. To check use Desmo graphing calculator and enter your equation for next time.

Answer:

AnBnC ( common place for all)

HAVE A NİCE DAY

Answer:

The answer is "840".

Step-by-step explanation:

Following are the number of ways in which selecting a team A  by 9 children:

[tex]= ^{9_{C_{3}}\\\\\\[/tex]

[tex]=\frac{9!}{3! \times 6!} \\\\=\frac{9\times 8\times 7\times 6!}{3 \times 2\times 1\times 6!}\\\\=\frac{9\times 8\times 7}{3 \times 2\times 1}\\\\=\frac{3\times 4\times 7}{1}\\\\=\frac{84}{1}\\\\=84[/tex]

Following are the number of ways in which selecting a team B  by remaining 6 children:

 [tex]= ^{6}_{C_{3}}[/tex]

[tex]= \frac{6!}{(3! \times 3!)}\\\\= \frac{6!}{(3\times 2\times 1 \times 3!)}\\\\= \frac{6\times 5 \times 4 \times 3!}{(3\times 2\times 1 \times 3!)}\\\\= \frac{ 5 \times 4 \times 3!}{3!}\\\\= 5 \times 4 \\\\=20[/tex]

Following are the number of ways in which selecting a team C  by remaining 3 children:

[tex]= ^{3}_{C_{3}}\\\\=\frac{3!}{3!}\\\\= 1[/tex]

Following are the number of ways in which making 3 teams by 9 children:

[tex]= \frac{(84 \times 20 \times 1)}{3!}\\\\= \frac{(84 \times 20 )}{6}\\\\= 14 \times 20\\\\= 280\\\\[/tex]

(Note: we've split by 3! Because it also is necessary to implement three teams between themselves)

Now 3 leagues have to be played. One is going to be run by each team.

That is the way it is

Different possible divisions

[tex]= 280 \times 3!\\\\= 280 \times (3 \times 2 \times 1)\\\\= 840[/tex]  

Answer:

A

Step-by-step explanation:

ITS OPTION (A)

PLZ MARK ME BRAINLIEST..

Answer:

2 days

Step-by-step explanation:

Lets say that in one day, one cow eats 1 block of grass. So, six cows in three days would eat 18 blocks of grass in total. So 18 blocks of grass is how much we have. that means nine cows would eat that much in 2 days.

Answer:

its a

Step-by-step explanation:

trust did test

I'm going to try my best to explain 90° rotation:

So, you know that if you rotate something 180°, it's completely flipped (think about spinning around half-way).

Or if you spin something 360°, you spin around the whole way and end up in the same spot that you did when you started.

Notice how 90 is actually 1/4 of 360.

So imagine spinning instead of 180, spinning half of that. so you barely rotate. That's exactly what you're doing to this shape here. and if you do it about the origin counterclockwise, the origin is (0,0) so I drew it in Quadrant III, as you can see in my attachment.

You can see that every point has been moved by 90°, I put all of the variables there so you could visualize it better!

I hope this helped, let me know if you have any questions! :)

Answer:

prove that The given system of equations is redundant is attached below

Step-by-step explanation:

System of equations

x1 +x2 −3x3 = 7

−2x1 +x2 +5x3 = 2

 3x2 −x3 = 16

To prove that the system is redundant we will apply the Gaussian elimination ( pivot operation )

attached below is the solution