Simplify the following expression. (10-4i)(4-5i)+(-15+20i)

Answer:

A. R=0.86; strong correlation

Step-by-step explanation:

The correlation coefficient of 0.29 indicates that the correlation is a weak positive correlation. Thus option (D) is the correct answer.

"Correlation is a statistical tool that studies the relationship between two variables. Data sets have a positive correlation when they increase together, and a negative correlation when one set increases as the other decreases".

For the given situation,

Correlation coefficient = 0.29

Positive correlation: the two variables change in the same direction.

Negative correlation: the two variables change in opposite directions.

No correlation: there is no association or relevant relationship between the two variables.

The correlation coefficient lies between 0 to 0.3 indicating that the correlation is a weak positive correlation.

Hence we can conclude that option (D) weak positive correlation is the correct answer.

Learn more about correlation here

https://brainly.com/question/10721912

#SPJ2

Answer:

the answer to this question is

B. 1/2

hope this helps u

Answer:

The sum of the series is Sₙ = n/2 [2·a + (n - 1)·d] where a = 8 and d = 8, therefore 8 + 16 + 24 + ... + 8·n = 4·n·(n + 1)

Step-by-step explanation:

The parameters given are;

8 + 16 + 24 + ... + 8·n = 4·n·(n + 1)

The given series of numbers can be checked to find;

16 - 8 = 24 - 16 = 8

Therefore, the series of numbers is an arithmetic progression with first term = 8, and common difference = 8, we have;

The sum of n terms of an arithmetic progression, Sₙ, is given as follows;

Sₙ = n/2 [2·a + (n - 1)·d]

Where;

a = The first term of the series of numbers = 8

d = The common difference = 8

∴ Sₙ = n/2 × [2×8 + (n - 1)×8] = n [2×8/2 + (n - 1)×8/2]  =  n × [8 + (n - 1)×4]

Sₙ =  n × [8 + (n - 1)×4] =  n × [8 + 4·n - 4] = n × [8  - 4 + 4·n] = n × [4 + 4·n]

Sₙ =n × [4 + 4·n] = 4 × n×(n + 1) = 4·n·(n + 1).

Answer:

7 is divided by 15 =0•4666666667

Let assume hours be x.

1 hour = 60 minutes

x hour = 330 minutes

[tex] \bf \large \rightarrow \: \: \frac{1}{60} \: \times \: \frac{x}{330} \: \: \: \small\rm({\red{ Cross \: \: Multiplying }}) \\ [/tex]

[tex]\bf \large \rightarrow \: \: 60x \: = \: 330[/tex]

[tex]\bf \large \rightarrow \: \: x \: = \: \cancel \frac{330}{60} \: = \: 5.5 \\ [/tex]

Total hours in a day is 5.5

The average American student is in class 5.5 hours a day.

A measurement unit is a standard quality used to express a physical quantity. Also it refers to the comparison between the unknown quantity with the known quantity.

We have to given that;

The average American student is in class 330 minutes a day.

We know that;

⇒ 1 hours = 60 minutes

⇒ 1 minute = 1/60 hours

Hence, We can change the unit as;

⇒ 330 minutes = 330 / 60 hours

                        = 5.5 hours

Thus, It is equal to 5.5 hours.

Learn more about the measurement unit visit:

https://brainly.com/question/777464

#SPJ2

Answer: 0

Work Shown:

Factors of 48 = {1, 2, 3, 4, 6, 8, 12, 16, 24, 48}

Erase the odd numbers of that list to get {2, 4, 6, 8, 12, 16, 24, 48}

Then highlight stuff that is greater than 24, and less than 48 at the same time.

No factors fit this description since 24 cannot be larger than itself, and 48 cannot be smaller than itself.

Answer: 0

Step-by-step explanation:

There is no number greater than 24 and less than 48.

Answer

x = 13 or x = 23

Step-by-step explanation:

|x-18| = 5 means there are two possibilities.

x-18 can equal 5 or equal -5 because absolute value sign makes everything inside it positive.

so you can write two equations and solve

first is x-18 = 5

x-18 + 18 = 5 + 18

x = 23

the second is x - 18 = -5

x - 18 + 18 = -5 + 18

x = 13

The two solutions are 13 and 23.

Answer:4:1 just taking to test as soon as you

Step-by-step explanation:

The ratio of fiction books to nonfiction books on the shelf is,  4

A ratio in mathematics is a comparison of two or more numbers that shows how big one is in comparison to the other. The dividend or number being divided is referred to as the antecedent, while the divisor or number that is dividing is referred to as the consequent.

Given that,

Ellie has 20 books on her shelf

Four of these books are nonfiction

The rest are fiction

The ratio of fiction books to nonfiction books on the shelf = ?

The number of fiction books = ?

The number of fiction books = 20 - 4

                                                 = 16

Ratio =    fiction/nonfiction

         =      16/4

          =    4

Hence, the ratio is 4

To know more about Ratio check:

https://brainly.in/question/7996583

#SPJ2

Answer:

y=3

Step-by-step explanation:

7y-(5y+4)=10

7y-5y+4=10

         -4    -4

7y-5y=6

2y=6

÷2   ÷2

y=3

Step-by-step explanation:

you can check the answer by putting 5 on the place of B... you will get the lateral surface area

118 m²...

hope it helps

Answer:

C....................

Answer:

(C) [tex]x=4[/tex]

Step-by-step explanation:

A line will be parallel to the y-axis if It’s x never changes.

In A, x is always being -y, so that’s going to change all the time.

In B, x is always becoming y, so that is changing too.

In C, x is always being 4, so this never changes.

In D, x is always 4 times y, so this changes.

Hope this helped!

Answer:

numbers that cannot be reduced when squared, ex: 1,3,5,

Step-by-step explanation:

These numbers factors are themselves and 1, to find if it is a prime number you can try to find the factors and if it is just itself and 1, then it is a prime number

Answer:

D. y = cos(4x)

Step-by-step explanation:

The graph passes through the points y = 0 and x = 3π/8

So you solve x = 3π/8 into 4 answers, which is equal to 0 is the correct answer.

Answer:

A

Step-by-step explanation:

Find the vertex form of the quadratic function below.

y = x^2 - 4x + 3

This quadratic equation is in the form y = a{x^2} + bx + cy=ax  

2

+bx+c. However, I need to rewrite it using some algebraic steps in order to make it look like this…

y = a(x - h)^2 + k

This is the vertex form of the quadratic function where \left( {h,k} \right)(h,k) is the vertex or the “center” of the quadratic function or the parabola.

Before I start, I realize that a = 1a=1. Therefore, I can immediately apply the “completing the square” steps.

STEP 1: Identify the coefficient of the linear term of the quadratic function. That is the number attached to the xx-term.

STEP 2: I will take that number, divide it by 22 and square it (or raise to the power 22).

STEP 3: The output in step #2 will be added and subtracted on the same side of the equation to keep it balanced.

Think About It: If I add 44 on the right side of the equation, then I am technically changing the original meaning of the equation. So to keep it unchanged, I must subtract the same value that I added on the same side of the equation.

STEP 4: Now, express the trinomial inside the parenthesis as a square of a binomial, and simplify the outside constants.

After simplifying, it is now in the vertex form y = a{\left( {x - h} \right)^2} + ky=a(x−h)  

2

+k where the vertex \left( {h,k} \right)(h,k) is \left( {2, - 1} \right)(2,−1).

Visually, the graph of this quadratic function is a parabola with a minimum at the point \left( {2, - 1} \right)(2,−1). Since the value of “aa” is positive, a = 1a=1, then the parabola opens in upward direction.

Example 2: Find the vertex form of the quadratic function below.

The approach to this problem is slightly different because the value of “aa” does not equal to 11, a \ne 1a  



​  

=1. The first step is to factor out the coefficient 22 between the terms with xx-variables only.

STEP 1: Factor out 22 only to the terms with variable xx.

STEP 2: Identify the coefficient of the xx-term or linear term.

STEP 3: Take that number, divide it by 22, and square.

STEP 4: Now, I will take the output {9 \over 4}  

4

9

​  

 and add it inside the parenthesis.

By adding {9 \over 4}  

4

9

​  

 inside the parenthesis, I am actually adding 2\left( {{9 \over 4}} \right) = {9 \over 2}2(  

4

9

​  

)=  

2

9

​  

 to the entire equation.

Why multiply by 22 to get the “true” value added to the entire equation? Remember, I factored out 22 in the beginning. So for us to find the real value added to the entire equation, we need to multiply the number added inside the parenthesis by the number that was factored out.

STEP 5: Since I added {9 \over 2}  

2

9

​  

 to the equation, then I should subtract the entire equation by {9 \over 2}  

2

9

​  

 also to compensate for it.

STEP 6: Finally, express the trinomial inside the parenthesis as the square of binomial and then simplify the outside constants. Be careful combining the fractions.

It is now in the vertex form y = a{\left( {x - h} \right)^2} + ky=a(x−h)  

2

+k where the vertex \left( {h,k} \right)(h,k) is \left( {{{ - \,3} \over 2},{{ - 11} \over 2}} \right)(  

2

−3

​  

,  

2

−11

​  

).

Example 3: Find the vertex form of the quadratic function below.

Solution:

Factor out - \,3−3 among the xx-terms.

The coefficient of the linear term inside the parenthesis is - \,1−1. Divide it by 22 and square it. Add that value inside the parenthesis. Now, figure out how to make the original equation the same. Since we added {1 \over 4}  

4

1

​  

 inside the parenthesis and we factored out - \,3−3 in the beginning, that means - \,3\left( {{1 \over 4}} \right) = {{ - \,3} \over 4}−3(  

4

1

​  

)=  

4

−3

​  

 is the value that we subtracted from the entire equation. To compensate, we must add {3 \over 4}  

4

3

​  

 outside the parenthesis.

Therefore, the vertex \left( {h,k} \right)(h,k) is \left( {{1 \over 2},{{11} \over 4}} \right)(  

2

1

​  

,  

4

11

​  

).

Example 4: Find the vertex form of the quadratic function below.

y = 5x^2 + 15x - 5  

Solution:

Factor out 55 among the xx-terms. Identify the coefficient of the linear term inside the parenthesis which is 33. Divide it by 22 and square to get {9 \over 4}  

4

9

​  

.

Add {9 \over 4}  

4

9

​  

 inside the parenthesis. Since we factored out 55 in the first step, that means 5\left( {{9 \over 4}} \right) = {{45} \over 4}5(  

4

9

​  

)=  

4

45

​  

 is the number that we need to subtract to keep the equation unchanged.

Express the trinomial as a square of binomial, and combine the constants to get the final answer.

Therefore, the vertex \left( {h,k} \right)(h,k) is {{ - \,3} \over 2},{{ - \,65} \over 4}  

2

−3

​  

,  

4

−65

​  

.

Answer:

(x - 1 )^2 - 3

Step-by-step explanation:

( x - 1 )^2 + ( -3)

x^2 - 2x + 1 - 3

x^2 - 2x - 2

Answer:

[tex]\frac{16}{81}[/tex]

Step-by-step explanation:

[tex](\frac{27}{8} )^{-\frac{4}{3} }[/tex]

[tex]=((\frac{3}{2} )^3)^{-4/3}[/tex]

[tex]=(\frac{3}{2} )^{-4}[/tex]

[tex]=(\frac{2}{3} )^{4}[/tex]

[tex]=\frac{16}{81}[/tex]

Answer:

16/81

Step-by-step explanation:

a negative exponent means 1/...

the number in the numerator means "to the power of".

the number in the denominator means take the root of that power.

so, we have to take the third root of the expression, or this then to the power of 4, and finally build 1/... if the whole result.

and the sequence is not making a difference.

the third root of of 27/8 = 3/2

this to the power of 4 = 81/16

this 1/... = 16/81

Answer:

Step-by-step explanation:

When you go shopping for anything, you know that the more of that something you buy, the more money you are going to spend. In other words, the amount of money you spend depends directly upon the amount of stuff you buy. So the number of boxes of cookies you buy is the independent variable and the amount of money you spend on the cookies is the dependent variable.

Answer:

59

Step-by-step explanation:

3x=177

3x represents the # of arrow he can shoot at once every time

177 represents the total # of arrow he has

Answer:

59

Step-by-step explanation:

177/3=59

Answer:

Hello,

a=0.5

Step-by-step explanation:

[tex]\left \{ \begin{array}{ccc}ax+2y&=&12\\8x+32y&=&144\\\end{array}\right.\\\\\\\Longleftrightarrow\ \left \{ \begin{array}{ccc}ax+2y&=&12\\x+4y&=&18\\\end{array}\right.\\\\\\\Longleftrightarrow\ \left \{ \begin{array}{ccc}(1-2a)x&=&-6\\x+4y&=&18\\\end{array}\right.\\\\if\ 1-2a\neq 0\ (or\ a\neq \dfrac{1}{2} )\ then\\\left \{ \begin{array}{ccc}x&=&\dfrac{6}{2a-1}\\\\y&=&\dfrac{18-\dfrac{6}{2a-1}}{4} \\\end{array}\right.\\\\[/tex]

[tex]\Longleftrightarrow\ \left \{ \begin{array}{ccc}x&=&\dfrac{6}{2a-1}\\\\y&=&\dfrac{ 3(3a-2)}{2a-1} \\\end{array}\right.\\\\[/tex]

else\

[tex]a=\dfrac{1}{2} \\\Longleftrightarrow\ \left \{ \begin{array}{ccc}\dfrac{1}{2} x+2y&=&12\\\\x+4y&=&18 \\\end{array}\right.\\\\\\\Longleftrightarrow\ \left \{ \begin{array}{ccc}x+4y&=&24\\\\x+4y&=&18 \\\end{array}\right.\\\\\\\Longleftrightarrow\ \left \{ \begin{array}{ccc}0=6\ !!!!!\\\end{array}\right.\\\\Syetem\ has\ no\ solution\\[/tex]

Answer:

x = 60/83

Step-by-step explanation:

Solve for x:

10 - (83 x)/6 = 0

Put each term in 10 - (83 x)/6 over the common denominator 6: 10 - (83 x)/6 = 60/6 - (83 x)/6:

60/6 - (83 x)/6 = 0

60/6 - (83 x)/6 = (60 - 83 x)/6:

(60 - 83 x)/6 = 0

Multiply both sides of (60 - 83 x)/6 = 0 by 6:

(6 (60 - 83 x))/6 = 6×0

(6 (60 - 83 x))/6 = 6/6×(60 - 83 x) = 60 - 83 x:

60 - 83 x = 6×0

0×6 = 0:

60 - 83 x = 0

Subtract 60 from both sides:

(60 - 60) - 83 x = -60

60 - 60 = 0:

-83 x = -60

Divide both sides of -83 x = -60 by -83:

(-83 x)/(-83) = (-60)/(-83)

(-83)/(-83) = 1:

x = (-60)/(-83)

Multiply numerator and denominator of (-60)/(-83) by -1:

Answer: x = 60/83

Answer:

16 ft

Step-by-step explanation:

Slant Height=sqrt(Radius^2+Height^2)

Height=sqrt(20^2-12^2)=sqrt(256)=16 ft

Answer:

The probability that the sample proportion of households spending more than $125 a week is between 0.36 and 0.42 is 0.3115

Step-by-step explanation:

From the question, we can deduce the following;

n = 75

p = 0.35

where q = 1-p = 1-0.35 = 0.65

To compute the probability that the sample proportion of households spending more than $125 a week is between 0.36 and 0.42, we start by calculating the standard deviation of sample proportion.

Mathematically;

Standard deviation of sample proportion = √pq/n

SD = √(0.35)(0.65)/75 = 0.055 which is approximately 0.06

Let’s now compute the z-scores

For 0.36, we have ; (0.36-0.35)/0.06 = 0.01/0.06 = 0.17

For 0.42, we have; (0.42-0.35)/0.06 = 0.07/0.06 = 1.17

So the probability we want to calculate is :

P(0.17<z<1.17) = P(z<1.17) - P(z < 0.17) = 0.8790 - 0.5675 = 0.3115

Answer:

S.D=46.04

Step-by-step explanation:

steps are in the picture.

If you have question about it you can ask.Thanks

Answer:

36 lbs

Step-by-step explanation:

let the weight of each boy's backpack be B and the weight of each girl's backpack be G.

Given that the total weight of all (i.e 10 boys' and 10 girls') backpacks equals 600 lbs,  i.e.

10B + 10G = 600   (simplifying by dividing both sides by 10)

B + G = 60 ------- eq 1

Also given that a girl's backpack is 1.5 times LESS than a boy's backpack.

written another way, we can say that a boy's backpack is 1.5 times MORE than a girl's backpack, or:

B = 1.5G   (rearranging)

B - 1.5G = 0     ------ eq 2

We can solve eq 1 and eq 2 by elimination,

(eq 1) - (eq 2)

(B + G) - (B - 1.5G) = 60 - 0

B + G - B + 1.5G = 60

G  + 1.5G = 60

2.5G = 60   (divide both sides by 2.5)

G = 60 / 2.5

G = 24 lbs   (substitute this into equation 1)

B + G = 60

B + 24 = 60

B = 60 - 24

B = 36 lbs

Answer:

Does the answer help you?

Answer:

a. Please check the explanation for filling of the empty column on the table

b. The mean of the random variable x is 7/11

Step-by-step explanation:

a. Firstly, we are concerned with completing the table.

To do this, we simply need to multiply the values in the column of x by the values in the column of p(x)

Thus, we have the following;

2. 3 * 2/36 = 6/36

3. 4 * 3/36 = 12/36

4. 5 * 4/36 = 20/36

5. 6 * 5/36 = 30/36

6. 7 * 6/36 = 42/36

7. 8 * 5/36 = 40/36

8. 9 * 4/36 = 36/36

9. 10 * 3/36 = 30/36

10. 11 * 2/36 = 22/36

11. 12 * 1/36 = 12/36

b. We want to find the mean of the random variable x.

All what we need to do here is add all the values of x•P(x) together, then divide by 11.

Thus, we have

(2/36 + 6/36 + 12/36 + 20/36 + 30/36 + 42/36 + 40/36 + 36/36 + 30/36 + 22/36 + 12/36)/11

Since the denominator is same for all, we simply add all the numerators together;

(252/36) * 11 = 252/396 = 63/99 = 7/11

compute the range of the figures into the table

[tex]\\ \sf\longmapsto g=b(a+D^2)[/tex]

[tex]\\ \sf\longmapsto g=ba+bD^2[/tex]

[tex]\\ \sf\longmapsto g-bD^2=ba[/tex]

[tex]\\ \sf\longmapsto a=\dfrac{g-bD^2}{b}[/tex]

or

[tex]\\ \sf\longmapsto a=\dfrac{g}{b}-D^2[/tex]

Answer:

Freedom is any case,

is only possible

by constantly

struggling for it.

Albert Einstein

Answer:

200.96

Step-by-step explanation:

Volume of cone=(1/3)*pi*r^2*h

Volume=(1/3)*pi*16*12=64*3.14=200.96

Answer:

a) b⁹

Step-by-step explanation:

b³ • b⁻⁵ • b¹¹

add the exponents

b³ ⁺ ⁽⁻⁵⁾ ⁺ ¹¹

b⁹

Answer:

b^9

Step-by-step explanation:

b^3·b^−5·b^11

Since the bases are the same, and we are multiplying, we can add the exponents

b^(3+-5+11)

b^9