Let R be a system consisting of rational expressions. Which operations are closed for R?

Answer:

D  [tex]\sqrt{x} +11=15[/tex]

Step-by-step explanation:

Edge 2020

For the given expression √x + 11 = 15 the value of x will be equal to 16.

The mathematical expression combines numerical variables and operations denoted by addition, subtraction, multiplication, and division signs.

Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also denote the logical syntax's operation order and other properties.

Given that the expression √x + 11 =15. The expression will be solved as below,

√x + 11 =15

√x = 15 - 11

√x = 4

Squaring on both sides of the equation,

x = 4²

x = 16

To know more about an expression follow

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Answer:

We have to remember

slope = m

if the slope of line is parellel so it will be the same with other slope

m1= m2

2/3= 2/3

so the answer is 2/3

hope it helps ^°^

Answer:

2/3

Step-by-step explanation:

Parallel lines have the same slopes. Therefore,

[tex]m_{k} =m_{p}[/tex]

The slope of line k ([tex]m_{k}[/tex]) will be equal to the slope of the line parallel to k ([tex]m_{p}[/tex]).

We know that the slope of line k is 2/3.

[tex]m_{k}=\frac{2}{3}[/tex]

Therefore, the slope of the line parallel to line k is also 2/3.

[tex]\frac{2}{3}=m_{p}[/tex]

The slope of a line parallel to line k is 2/3.

Answer:

-7.

Step-by-step explanation:

g(x) = x^2 - 6x - 7

g(2) = 2^2 - 6(2) - 7

= 4 - 12 - 7

= -8 - 7

= -15

f(x) = x + 8

f(-15) = (-15) + 8

= 8 - 15

= -7

Hope this helps!

Answer:

3x^2 + 3xy/2 - 7xy^2/2

Step-by-step explanation:

So we know the perimeter is 20x^2 + xy - 7y^2,

To find any perimeter you need 2l + 2w = P so,

One of the sides is 7x^2 - xy

First plug in the values,

2(7x^2-xy) + 2w = 20x^2 + xy - 7y^2

Multiply,

14x^2-2xy + 2w = 20x^2 + xy - 7y^2

Subtract,

14x^2 - 2xy - 14x^2 + 2xy + 2w = 20x^2 + xy - 7y^2 - 14x^2 + 2xy

2w = 6x^2 + 3xy - 7y^2

w = 3x^2 + 3xy/2 - 7xy^2/2

Answer:

We conclude that no more than 10% of its microwaves need repair during the first five years of use.

Step-by-step explanation:

We are given that a maker of microwave ovens advertises that no more than 10% of its microwaves need repair during the first 5 years of use.

In a random sample of 50 microwaves that are 5 years old, 12% needed repairs.

Let p = population proportion of microwaves who need repair during the first five years of use.

So, Null Hypothesis, [tex]H_0[/tex] : p [tex]\leq[/tex] 10%      {means that no more than 10% of its microwaves need repair during the first five years of use}

Alternate Hypothesis, [tex]H_A[/tex] : p > 10%     {means that more than 10% of its microwaves need repair during the first five years of use}

The test statistics that will be used here is One-sample z-test for proportions;

                        T.S.  =  [tex]\frac{\hat p-p}{\sqrt{\frac{p(1-p)}{n} } }[/tex]  ~ N(0,1)

where, [tex]\hat p[/tex] = sample proportion of microwaves who need repair during the first 5 years of use = 12%

           n = sample of microwaves = 50

So, the test statistics =  [tex]\frac{0.12-0.10}{\sqrt{\frac{0.10(1-0.10)}{50} } }[/tex]

                                    =  0.471

The value of z-test statistics is 0.471.

Now, at a 0.04 level of significance, the z table gives a critical value of 1.751 for the right-tailed test.

Since the value of our test statistics is less than the critical value of z as 0.471 < 1.751, so we have insufficient evidence to reject our null hypothesis as the test statistics will not fall in the rejection region.

Therefore, we conclude that no more than 10% of its microwaves need repair during the first five years of use.

Answer:

Use the student t distribution

Step-by-step explanation:

Here is the formula

t = (x - u) ÷(s/√N)

From the information we have in the question:

n = 150

s = 550

x = 3400

u = mean = 2400

= 3400 - 2400÷ 500/√150

= 1000/44.9

= 22.27

At 0.05 significance level, df = 149 so t tabulated will be 1.65.

Answer:

Step-by-step explanation:

Hello, by definition a perfect square can be written as [tex]a^2[/tex] where a in a positive integer.

So, to answer the first question, [tex]6^2[/tex] is a perfect square.

(a,b,c) is a Pythagorean triple means the following

[tex]a^2+b^2=c^2[/tex]

Here, it means that

[tex]x^2=20^2+21^2=841=29^2 \ \ \ so\\\\x=29[/tex]

Thank you.

Answer:

Its B

Step-by-step explanation:

Answer:

$52

Step-by-step explanation:

$52. Since Alex pays for car insurance twice a year, divide the cost of each payment by 6, the number of months in half a year. This will tell you how much money Alex needs to set aside each month to cover his insurance costs.

312÷6=52

Complete Question

The  complete question is shown on the first uploaded image

Answer:

The correct option is  D

Step-by-step explanation:

From the question the question we are told that

    The researchers were able to state that they are 95% confident that between 52.5% and 59.5% of all U.S. adults believe that the U.S. federal government is not doing enough to keep U.S. elections safe.

Generally a confidence interval states to what extent the chances of the true population is within the a given range

 So the 95% confidence interval given in the question as 52.5% and 59.5%  means that the chances of the true population mean being with this given range is 95%

 So given that the the true population mean is within this range then it means that the population mean will be greater than 50%

   So  the statement that best describe and interprets this result is

The results show significant statistical support that most U.S. adults (over 50%) believe that the U. S. Federal government is not doing enough to keep U.S. election safe.

Answer:

Step-by-step explanation:

6x³ - 4x² - 16x

To factorize the expression first factor out the GCF out

The GCF in the expression is 2x

That's

2x( 3x² - 2x - 8)

Next Factorize the terms in the bracket

To factorize write - 2x as a difference

that's

2x( 3x² + 4x - 6x - 8)

Factor out x from the expression

2x [ x( 3x + 4) - 6x - 8 ]

Next factor out - 2 from the expression

2x [ x ( 3x + 4) - 2( 3x + 4) ]

Factor out 3x + 4 from the expression

We have the final answer as

Hope this helps you

[tex]|\Omega|=2\cdot6=12\\|A|=1\cdot2=2\\\\P(A)=\dfrac{2}{12}=\dfrac{1}{6}[/tex]

The shape has 11 sides.

Using the angle formula for polygons:

The sum of all the interior angles is:

11-2 x 180 = 9 x 180 = 1,620 degrees.

For one angle divide the total by number of sides:

1620 / 11 = 147.27 which rounds to 147.2

The answer is D.

Answer:

60 Feet =  18.288 Meters

Step-by-step explanation:

foot = 12 inch = 0.3048 m

0.3047 × 60

18.288 meters

Answer: -7

Step-by-step explanation:

To find f(-8) look at the f function. Find the y value when x = -8

To find g(4) look at the g function. Find the y value when x = 3

Plug these values into the equation

-1 f(-8) - 4 f(4)

-1 (-5) - 4 (3)

5 - 12 = -7

Answer:

I know the answer

Step-by-step explanation:

Linear functions are those whose graph is a straight line. A linear function has the following form. y = f(x) = a + bx. A linear function has one independent variable and one dependent variable. The independent variable is x and the dependent variable is y.

Answer:

The  95% confidence interval is  [tex]295.9 < \mu< 324.1[/tex]

A   95% level of confidence mean that there is 95%  chance  that the true population mean will be in this interval

Step-by-step explanation:

From the question we are told that

    The sample size is  [tex]n = 25[/tex]

    The mean is  [tex]\= x = 310 \ mg[/tex]

     The standard deviation is  [tex]\sigma = 36 \ mg[/tex]

Given that the confidence level is  95% then the level of significance is mathematically represented as

           [tex]\alpha = 100 - 95[/tex]

=>        [tex]\alpha = 5\%[/tex]

=>        [tex]\alpha = 0.05[/tex]

Next we obtain the critical value of  [tex]\frac{\alpha }{2}[/tex] from the normal distribution table , the value is  

           [tex]Z_{\frac{\alpha }{2} } =Z_{\frac{0.05 }{2} } = 1.96[/tex]

Generally the margin of error is mathematically represented as

        [tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]

substituting values

        [tex]E = 1.96 * \frac{36 }{\sqrt{25} }[/tex]

        [tex]E = 14.1[/tex]

The 95% level of confidence interval  is mathematically represented as

      [tex]\= x - E < \mu<\ \= x - E[/tex]

substituting values

     [tex]310- 14.1 < \mu< 310+ 14.1[/tex]

     [tex]295.9 < \mu< 324.1[/tex]

The  95% level of confidence mean that there is 95%  chance  that the true population mean will be in this interval

Answer:36

Step-by-step explanation:

Answer:

ŷ = 0.964X1 - 0.336X2 + 13.066

b1 = 0.964 which is the unit change in the value of y when x1 changes.

b2 = - 0.336 which is the unit change in the value of y when x2 changes

Step-by-step explanation:

Y

10

11

15

15

20

23

27

32

X1

1

5

5

9

7

11

16

21

X2

16

11

14

11

1

8

7

3

The general form of a multiple regression equation is in form:

ŷ = b1x1 + b2x2 + c

Where,

ŷ = predicted or dependent variable

b1 and b2 = slope or gradient Coefficient for the independent or predictor variables x1 and X2 respectively.

c = intercept (constant)

Using the online multiple regression calculator, the model obtained by Inputting the values is written below:

ŷ = 0.964X1 - 0.336X2 + 13.066

Value of b1 = 0.964 which is the unit change in the value of y when x1 changes.

Value b2 = - 0.336 which is the unit change in the value of y when x2 changes

Answer:

[tex]x = 7[/tex]

Step-by-step explanation:

We can solve the equation [tex]5x+3+8x-4=90[/tex] by isolating the variable x on one side. To do this, we must simplify the equation.

[tex]5x+3+8x-4=90[/tex]

Combine like terms:

[tex]13x - 1 = 90[/tex]

Add 1 to both sides:

[tex]13x = 91[/tex]

Divide both sides by 13:

[tex]x = 7[/tex]

Hope this helped!

Answer:

x = 7

Step-by-step exxplanation:

5x + 3 + 8x - 4 = 90

5x + 8x = 90 - 3 + 4

13x = 91

x = 91/13

x = 7

probe:

5*7 + 3 + 8*7 - 4 = 90

35 + 3 + 56 - 4 = 90

Answer:

A = 12 square units

Step-by-step explanation:

Area of a Triangle = base * height / 2

The triangle might look weird and doesn't look like it has a base, but if you look at the left side you see there is a straight line which means there is a base, so we flip the picture until we see that the flat line on the bottom or the base.

The base is 4 units.

To find the height, we don't need a straight line, we just need to see how the tall the triangle is, to do that you must start from the lowest point and count up to the highest point.

You now get 6 units.

A = bh/2

A = 4*6/2

A = 24/2

A = 12 square units

Answer:

42 minutes

Step-by-step explanation:

if you are asking how long it takes Chelsea to play her tuba then you do:       67 - 25 = 42

Answer:

Step-by-step explanation:

jhngjnh

Answer:

(2-j)(4-y)

Step-by-step explanation:

Factoring using grouping,

(2-j)(4-y)

Answer:

None of the above.

1.86p + 0.7

Step-by-step explanation:

Step 1: Write expression

0.7 + p + 0.86p

Step 2: Combine like terms

0.7 + 1.86p

None of those answer choices are correct unless you wrote the problem incorrectly.

Answer:

If we have an integer number N, the opposite of N will be:

-1*N = -N.

Then, the opposite of 0°C is:

-1*0°C = 0°C.

The number 0 is it's own opposite.

And for 32F, the opposite is:

-1*32F = -32F

So, while the numbers 0°C and 32F physically represent the same thing (the same temperature), mathematically, they behave differently.

Answer:

The​ z-score for 1880 is 1.34.

The​ z-score for 1190 is -0.88.

The​ z-score for 2130 is 2.15.

The​ z-score for 1350 is -0.37.

And the z-score of 2130 is considered to be unusual.

Step-by-step explanation:

The complete question is: A standardized​ exam's scores are normally distributed. In recent​ years, the mean test score was 1464 and the standard deviation was 310. The test scores of four students selected at random are ​1880, 1190​, 2130​, and 1350. Find the​ z-scores that correspond to each value and determine whether any of the values are unusual. The​ z-score for 1880 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 1190 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 2130 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 1350 is nothing. ​(Round to two decimal places as​ needed.) Which​ values, if​ any, are​ unusual? Select the correct choice below​ and, if​ necessary, fill in the answer box within your choice. A. The unusual​ value(s) is/are nothing. ​(Use a comma to separate answers as​ needed.) B. None of the values are unusual.

We are given that the mean test score was 1464 and the standard deviation was 310.

Let X = standardized​ exam's scores

The z-score probability distribution for the normal distribution is given by;

                          Z  =  [tex]\frac{X-\mu}{\sigma}[/tex]  ~ N(0,1)

where, [tex]\mu[/tex] = mean test score = 1464

           [tex]\sigma[/tex] = standard deviation = 310

S, X ~ Normal([tex]\mu=1464, \sigma^{2} = 310^{2}[/tex])

Now, the test scores of four students selected at random are ​1880, 1190​, 2130​, and 1350.

So, the z-score of 1880 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                      =  [tex]\frac{1880-1464}{310}[/tex]  = 1.34

The z-score of 1190 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{1190-1464}{310}[/tex]  = -0.88

The z-score of 2130 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{2130-1464}{310}[/tex]  = 2.15

The z-score of 1350 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{1350-1464}{310}[/tex]  = -0.37

Now, the values whose z-score is less than -1.96 or higher than 1.96 are considered to be unusual.

According to our z-scores, only the z-score of 2130 is considered to be unusual as all other z-scores lie within the range of -1.96 and 1.96.

Answer:

6x + 6 = 32

6x = 32 - 6

6x = 26

divide both sides by 6

6x/6 = 26/6

6x + 6 = 4.35

9x - 9 = 24

9x = 24 + 9

9x = 33

divide both sides by 9

9x/9 = 24/9

9x + 9 = 2.66

9x + 9 = 2.66

Answer: x=3

Step-by-step explanation:

[tex]\frac{32}{24} =\frac{4}{3} \\\\\frac{4}{3}=\frac{6x+6}{9x-9}\\ x=3[/tex]

Answer:

[tex]\huge\boxed{y = 8}[/tex]

Step-by-step explanation:

-4x + 3y = 12

Given that x = 3

-4 (3) + 3y = 12

-12 + 3y = 12

Adding 12 to both sides

3y = 12+12

3y = 24

Dividing both sides by 3

y = 8

Answer:

y =8

Step-by-step explanation:

-4x + 3y = 12

Let x = 3

-4(3) +3y = 12

-12+3y = 12

Add 12 to each side

-12+12+3y =12+12

3y =24

Divide each side by 3

3y/3 = 24/3

y =8

Answer:

x = -19

Step-by-step explanation:

13x + 14 = 12x - 5

subtract 12x from both sides

x + 14 = -5

subtract 14 from both sides

x = -19

Answer:

x= -19

Step-by-step explanation:

13x+14=12x−5

Subtract 12x from both sides.

13x+14−12x=−5

Combine 13x and −12x to get x.

x+14=−5

Subtract 14 from both sides.

x=−5−14

Subtract 14 from −5 to get −19

x=−19

Answer: (3x^2-1)(4x-3)

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

Work Shown:

Use the factor by grouping method

12x^3-9x^2-4x+3

(12x^3-9x^2)+(-4x+3)

3x^2(4x-3)-1(4x-3)

(3x^2-1)(4x-3)