25
Which expression represents half the sum of n and 7 ?

Answer:

The correct option is (A).

Step-by-step explanation:

If the reduced row echelon form of the coefficient matrix of a linear system of equations in four different variables has a pivot, i.e. 1, in each column, then the reduced row echelon form of the coefficient matrix is say A is an identity matrix, here I₄, since there are 4 variables.

[tex]\left[\begin{array}{cccc}1&0&0&0\\0&1&0&0\\0&0&1&0\\0&0&0&1\end{array}\right][/tex]

Then the corresponding augmented matrix [ A|B] , where the matrix is the representation of the linear system is AX = B, must be:

[tex]\left[\begin{array}{ccccc}1&0&0&0&a\\0&1&0&0&b\\0&0&1&0&c\\0&0&0&1&d\end{array}\right][/tex]

Now the given linear system is consistent as the right most column of the augmented matrix is a linear combination of the columns of A as the reduced row echelon form of A has a pivot in each column.

Thus, the correct option is (A).

Answer:

All real numbers greater than or equal to -3

Step-by-step explanation:

First look at graph where the line points to which direction of the graph

And look for any closed or open circles in the graph

Since in the graph has a close circle at (-3,-2) meaning it includes that x-value for its domain.

With the graph going to positive infinity it states that the domain is all real numbers.

So in conclusion it has a domain of all real numbers greater than or equal to -3

Answer:

ofn

Step-by-step explanation:

Answer:

Step-by-step explanation:

Since there are 44 average people out of 80. We can do this,

Total students : 600

Checked: 80

Average: 44

Number of averaged throughout the school: 600/80 * 44

                                                                        l: 7.5 * 44

Thus it is: 330 average students

-4y ≤ -12

Divide both sides by -4:

y ≤ 3

Because both sides were divided by a negative value you need to reverse the inequality sign:

y ≥ 3

Answer:

y = 3

Step-by-step explanation:

it says -4y ≤ -12 sooooooo    4 x 3 = 12!!!! so y = 3

Answer:

Step-by-step explanation:

it is -12 because -6 plus -6 is also like 6 plus 6

and then you have to add the negative Sign.

pls brainliest me

-6 - 6 = - 12

Happy to help! Please mark as the brainliest!

Answer:[tex]y=-\frac{3}{2} x+12[/tex]

Step-by-step explanation:

Perpendicular lines have inversely proportional slopes. So make the slope negative and switch it to its reciprocal.

2/3x would change into -3/2x

Lets write that down for a starting point for our perpendicular line.

y = -3/2x + b

We were given the x and y value via the coords. x = 12 and y = -6

Now we have -6 = -3/2(12) + b. Multiply -3 and 12 to get -36, then divide by 2 to get -18.  Now it's -6 = -18 + b. Solve for b by adding 18 to both sides to get b = 12

Answer:

8/3

Step-by-step explanation:

6(x-2)=4

x-2=4/6

x= 8/3

Answer:

x = 8/3

Step-by-step explanation:

Use Distributive Property

6(x-2) = 4

6x -12 = 4

add 12 on both sides

6x = 16

Divide by 6

x = 8/3

In decimal form: 2.667

Answer:

Car: 60%

Motorcycle: 30%

Truck: 10%

Step-by-step explanation:

Car: [tex]\frac{12}{12+6+2} =\frac{12}{20} =\frac{60}{100}[/tex] or 60%

Motorcycle: [tex]\frac{6}{12+6+2} =\frac{6}{20} =\frac{30}{100}[/tex] or 30%

Truck: [tex]\frac{2}{12+6+2} =\frac{2}{20} =\frac{10}{100}[/tex] or 10%

Answer:

Dear Laura Ramirez

Answer to your query is provided below

1) option A is correct

2) option B is correct

Step-by-step explanation:

Explanation for the first question attached in image

Also note - The converse of the hinge theorem states that if two triangles have two congruent sides, then the triangle with the longer third side will have a larger angle opposite that third side.

Answer:

1) option A is correct2) option B is correct

Step-by-step explanation:

Answer:

The z-score when x=187 is 2.41. The mean is 187. This z-score tells you that x = 187 is 2.41 standard deviations above the mean.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question:

[tex]\mu = 152, \sigma = 14.5[/tex]

The z-score when x=187 is ...

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{187 - 152}{14.5}[/tex]

[tex]Z = 2.41[/tex]

The z-score when x=187 is 2.41. The mean is 187. This z-score tells you that x = 187 is 2.41 standard deviations above the mean.

Answer:

655 people would need to be surveyed.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

In this question, we have that:

[tex]\pi = 0.68[/tex]

The margin of error is:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

90% confidence level

So [tex]\alpha = 0.1[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].

How many people would need to be surveyed for a 90% confidence interval to ensure the margin of error would be less than 3%?

We need to survey n adults.

n is found when M = 0.03. So

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.03 = 1.645\sqrt{\frac{0.68*0.32}{n}}[/tex]

[tex]0.03\sqrt{n} = 1.645\sqrt{0.68*0.32}[/tex]

[tex]\sqrt{n} = \frac{1.645\sqrt{0.68*0.32}}{0.03}[/tex]

[tex](\sqrt{n})^{2} = (\frac{1.645\sqrt{0.68*0.32}}{0.03})^{2}[/tex]

[tex]n = 654.3[/tex]

Rounding up

655 people would need to be surveyed.

Answer:

answer d) 20

Step-by-step explanation:

Because the two lines are parallel two by two, the figure is a parallelogram.

In a parallelogram the opposite corners are identical.

Given:

opposite corner1 = 130°

opposite corner2= (6a + 10)°

Because corner1 = corner2 we now have:

(6a + 10) = 130

6a + 0 = 130 -10

6a = 120

a = 20

Which is answer d).

Functions

Vertical Line Test

Let's see what we are given.

We are given a graph of an inverse of a function.

We need to figure out whether the graphed inverse function is a function or not.

By the definition of a function, we know that every x input must correlate with one y output. In layman's terms, each respective x input has its own specific y output.

This definition builds the foundation of the Vertical Line Test. We can use this simple "tool" to verify whether or not a given graph is a function or not.

When we apply the Vertical Line Test to the graphed inverse function, we can see that every x input has only one specific y output.

∴ we can conclude that the graphed inverse function is indeed a function.

The answer to the question would be A. True.

___

Learn more about functions: https://brainly.com/question/30017262

Learn more about Algebra I: https://brainly.com/question/17011730

___

Topic: Algebra I

Unit: Functions

Answer:

A-8

Step-by-step explanation:

Any other higher number plugged in makes the equation false

Answer:

E. 400

Step-by-step explanation:

So this is how we set this up, and how we solve

[tex]0.25x=100\\x=100/0.25\\x=400[/tex]

Hope this helps!

So you are solving for circumference of a quarter circle: [tex]\frac{1}{4}2 \pi r[/tex]

r= 28

[tex]\pi=3.14[/tex]

[tex]\frac{1}{4}2(87.92)=\\43.96[/tex]

Answer:

C.

Step-by-step explanation:

[tex]\frac{1}{5} +\frac{5}{6}[/tex] ≈ 1

5 + 8 + 1 = 14

Answer:

answer for the question is 130 length

Answer: 2

Step-by-step explanation:

9 × 2 - 16

18 - 16

2

Answer: 4/3

Step-by-step explanation:

As you know this graph is a lemniscate

[tex]4\int\limits^1_0 {x\sqrt{1-x^{2} } \, dx =\frac{4}{3} =1.33$[/tex]

Answer:

C............PAC-MAN

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

(2,1) - only one in the table. Remember (x,y)

Answer:

(a)[tex]\dfrac{2}{13}[/tex]

(b)[tex]\dfrac{3}{13}[/tex]

(c)[tex]\dfrac{4}{13}[/tex]

Step-by-step explanation:

In a standard deck, there are 52 cards which are divided into 4 suits.

(a)

Number of Seven Cards =4

Number of King cards =4

Probability of randomly selecting a seven or king

=P(Seven)+P(King)

[tex]=\dfrac{4}{52} +\dfrac{4}{52} \\=\dfrac{8}{52}\\=\dfrac{2}{13}[/tex]

(b)

Number of Seven Cards =4

Number of King cards =4

Number of Jack(J) cards =4

Probability of randomly selecting a seven or king

=P(Seven)+P(King)+P(Jack)

[tex]=\dfrac{4}{52} +\dfrac{4}{52}+\dfrac{4}{52} \\=\dfrac{12}{52}\\=\dfrac{3}{13}[/tex]

(c)

Number of Queen Cards =4

Number of Spade cards =13

Number of Queen and Spade cards =1

Probability of randomly selecting a seven or king

[tex]=P$(Queen)+P(Spade)-P(Queen and Spade Card)\\=\dfrac{4}{52} +\dfrac{13}{52} -\dfrac{1}{52} \\=\dfrac{16}{52} \\=\dfrac{4}{13}[/tex]

Answer:

385 ways

Step-by-step explanation:

Given;

7 red balls

10 white balls

In how many ways can 4 balls be selected if there are more than 2 red balls.

Selecting 4 balls which must contain more than 2 red balls, will be 3 red balls and 1 white ball to make it 4 in total, or all the 4 balls selected will red balls.

= 3 red balls and 1 white ball  OR 4 red balls

= 7C₃ x 10C₁  + 7C₄

[tex]= \frac{7!}{4!3!} *\frac{10!}{9!1!} \ \ + \ \frac{7!}{3!4!} \\\\= (35*10) \ + \ 35\\\\= 350 \ + 35\\\\= 385 \ ways[/tex]

Therefore, there are 385 ways of selecting 4 balls, if there are more than 2 red balls.

Answer:

So we can use geometric progression each time multiplying by 0.0475

so thats (275*0.0475)*10

So that means that we would get

130.625 so we subtract that from 275

275-130.625=144.375

That would be

Step-by-step explanation:

Answer:

16.67% probability of getting 2 blues

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

The order in which the marbles are selected is not important. So we use the combinations formula to solve this question.

Combinations formula:

[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]

What is the probability of getting 2 blues?

Desired outcomes:

Two blue marbles, from a set of 4.

[tex]D = C_{4,2} = \frac{4!}{2!(4-2)!} = 6[/tex]

Total outcomes:

Two marbles, from a set of 9.

[tex]T = C_{9,2} = \frac{9!}{2!(9-2)!} = 36[/tex]

Probability:

[tex]p = \frac{D}{T} = \frac{6}{36} = 0.1667[/tex]

16.67% probability of getting 2 blues

Answer:

C

Step-by-step explanation:

Given

x + 10 = 3(x - 1)² ← expand (x - 1)² using FOIL

x + 10 = 3(x² - 2x + 1) ← distribute

x + 10 = 3x² - 6x + 3 ← subtract x + 10 from both sides

0 = 3x² - 7x - 7 → C

Answer:

Step-by-step explanation:

Answer:

Test statistic t = 5.25

P-value = 0.000002 (one-tailed test)

Step-by-step explanation:

This is a hypothesis test for the population mean.

The claim is that the average amount of time that a freshman at TAMU studies is significantly higher than 7 hours.

Then, the null and alternative hypothesis are:

[tex]H_0: \mu=7\\\\H_a:\mu> 7[/tex]

The significance level is 0.05.

The sample has a size n=49.

The sample mean is M=8.5.

As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=√s^2=√4=2.

The estimated standard error of the mean is computed using the formula:

[tex]s_M=\dfrac{s}{\sqrt{n}}=\dfrac{2}{\sqrt{49}}=0.29[/tex]

Then, we can calculate the t-statistic as:

[tex]t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{8.5-7}{0.29}=\dfrac{1.5}{0.29}=5.25[/tex]

The degrees of freedom for this sample size are:

[tex]df=n-1=49-1=48[/tex]

This test is a right-tailed test, with 48 degrees of freedom and t=5.25, so the P-value for this test is calculated as (using a t-table):

[tex]\text{P-value}=P(t>5.25)=0.000002[/tex]

As the P-value (0.000002) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the average amount of time that a freshman at TAMU studies is significantly higher than 7 hours.

Answer:

Step-by-step explanation:

REcall that given a set A, * is a equivalence relation over A if

- for a in A, then a*a.

- for a,b in A. If a*b, then b*a.

- for a,b,c in A. If a*b and b*c then a*c.

Consider A the set of all ordered pairs of positive integers.

- Let (a,b) in A. Then a+b = a+b. So, by definition (a,b)R(a,b).

- Let (a,b), (c,d) in A and suppose that (a,b)R(c,d) . Then, by definition a+d = b+c. Since the + is commutative over the integers, this implies that d+a = c+b. Then (c,d)R(a,b).

- Let (a,b),(c,d), (e,f) in A and suppose that (a,b)R(c,d) and (c,d)R(e,f). Then

a+d = b+c, c+f = d+e.  We have that f = d+e-c. So a+f = a+d+e-c. From the first equation we find that a+d-c = b. Then a+f = b+e. So, by definition (a,b)R(e,f).

So R is an equivalence relation.

[(a,b)] is the equivalence class of (a,b). This is by definition, finding all the elements of A that are equivalente to (a,b).

Let us find all the possible elements of A that are equivalent to (2,4). Let (a,b)R(2,4) Then a+4 = b+2. This implies that a+2 = b. So all the elements of the form (a,a+2) are part of this class.

Answer: -6m-n+3

Step-by-step explanation:

The answer is -6m-n+3 because -3

times 2m is -6m and -n stays the same its outside of the parenthesis

and lastly -3 times -1 is positive 3

so answer maches up with the last one

the answer is -6m-n+3

Hope this helps :)

Answer:

-6m-n+3

Step-by-step explanation:

-3 x 2 is -6m (n stays same)

-3 x -1 is whole or positive 3

put it together and u get -6m-n+3

hope this helps

Answer:

Step-by-step explanation:

Confidence interval for the difference in the two proportions is written as

Difference in sample proportions ± margin of error

Sample proportion, p= x/n

Where x = number of success

n = number of samples

For the first brochure,

x = 100

n1 = 500

p1 = 100/500 = 0.2

For the second brochure

x = 125

n2 = 500

p2 = 125/500 = 0.25

Margin of error = z√[p1(1 - p1)/n1 + p2(1 - p2)/n2]

To determine the z score, we subtract the confidence level from 100% to get α

α = 1 - 0.95 = 0.05

α/2 = 0.05/2 = 0.025

This is the area in each tail. Since we want the area in the middle, it becomes

1 - 0.025 = 0.975

The z score corresponding to the area on the z table is 1.96. Thus, the z score for confidence level of 95% is 1.96

Margin of error = 1.96 × √[0.2(1 - 0.2)/500 + 0.25(1 - 0.25)/500]

= 1.96 × √0.000695

= 0.052

Confidence interval = (0.2 - 0.25) ± 0.052

= - 0.05 ± 0.052