I need help! I will give brainliest, if correct!

For a certain value of $k$, the system

x + y + 3z = 10,

-4x + 3y + 5z = 7,

kx + z = 3

has no solutions. What is this value of k?

Answers

Answer 1

kx + z = 3 means z = 3 - kx. Substitute this into the first two equations:

x + y + 3 (3 - kx) = 10   ==>   (1 - 3k) x + y = 1

-4x + 3y + 5 (3 - kx) = 7   ==>   (-4 - 5k) x + 3y = -8

Multiply through the first equation by -3 :

-3 ((1 - 3k) x + y) = -3 (1)   ==>   (-3 + 9k) x - 3y = -3

Add this to the second equation to eliminate y :

((-3 + 9k) x - 3y) + ((-4 - 5k) x + 3y) = -3 + (-8)

(-7 + 4k) x = -11

Normally, you would solve for x by dividing both sides by -7 + 4k. But you can't do that if this turns out to be equal to 0, which happens for

-7 + 4k = 0   ==>   k = 7/4

Answer 2

Answer:

k = 7/4

Step-by-step explanation:

I Need Help! I Will Give Brainliest, If Correct!For A Certain Value Of $k$, The Systemx + Y + 3z = 10,

Related Questions

The scatterplot shows the attendance at a pool for different daily high temperatures.

A graph titled pool attendance has temperature (degrees Fahrenheit) on the x-axis, and people (hundreds) on the y-axis. Points are at (72, 0.8), (75, 0.8), (77, 1.1), (82, 1.4), (87, 1.5), (90, 2.5), (92, 2.6), (95, 2.6), (96, 2.7). An orange point is at (86, 0.4).

Complete the statements based on the information provided.

The scatterplot including only the blue data points shows
✔ a strong positive
association. Including the orange data point at (86, 0.4) would
✔ weaken
the correlation and
✔ decrease
the value of r.

Answers

Answer:

✔ a strong positive

✔ weaken

✔ decrease

ED2021

Answer:

The scatterplot including only the blue data points shows  

✔ a strong positive

association. Including the orange data point at (86, 0.4) would  

✔ weaken

the correlation and  

✔ decrease

the value of r.

Step-by-step explanation:

A sample of 1700 computer chips revealed that 35% of the chips do not fail in the first 1000 hours of their use. The company's promotional literature claimed that over 32% do not fail in the first 1000 hours of their use. Is there sufficient evidence at the 0.02 level to support the company's claim

Answers

Answer:

The p-value of the test is 0.004 < 0.02, which means that there is sufficient evidence at the 0.02 level to support the company's claim.

Step-by-step explanation:

The company's promotional literature claimed that over 32% do not fail in the first 1000 hours of their use.

At the null hypothesis, we test if the proportion is of at most 32%, that is:

[tex]H_0: p \leq 0.32[/tex]

At the alternative hypothesis, we test if the proportion is more than 32%, that is:

[tex]H_1: p > 0.32[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.32 is tested at the null hypothesis:

This means that [tex]\mu = 0.32 \sigma = \sqrt{0.32*0.68}[/tex]

A sample of 1700 computer chips revealed that 35% of the chips do not fail in the first 1000 hours of their use.

This means that [tex]n = 1700, X = 0.35[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.35 - 0.32}{\frac{\sqrt{0.32*0.68}}{\sqrt{1700}}}[/tex]

[tex]z = 2.65[/tex]

P-value of the test and decision:

The p-value of the test is the probability of finding a sample proportion above 0.35, which is 1 subtracted by the p-value of z = 2.65.

Looking at the z-table, z = 2.65 has a p-value of 0.9960.

1 - 0.9960 = 0.004.

The p-value of the test is 0.004 < 0.02, which means that there is sufficient evidence at the 0.02 level to support the company's claim.

Determine the critical values for the confidence interval for the population standard deviation from the given values. Round your answers to three decimal places.
n = 12 and c = 0.9.

Answers

Answer:

The answer is "[tex]\chi^2_{L} = 4.575 \ and\ \chi^2_{U}= 19.675[/tex]"

Step-by-step explanation:

[tex]n=12\\\\\ c= 0.9[/tex]

Calculating the level of significance [tex](\alpha) = 1 -c[/tex]

                                                                  [tex]=1-0.9\\\\=0.1[/tex]

Calculating the degrees of freedom:

[tex]df=n-1=12-1=11[/tex]

Calculating the critical value:

Applying the Chi-Square table, the critical values for the two-tailed test with a degree of freedom  (11) for the significance level of [tex]\alpha = 0.1[/tex]:

[tex]\chi^2_{L} = 4.575 \\\\\chi^2_{U}= 19.675[/tex]

I need help so what’s 6 divide by 2(1+2)=

Answers

Answer:

9

Step-by-step explanation:

Divide 6 by 2:

3(1+2)

Add 1 and 2:

3 x 3

Multiply 3 by 3:

3 x 3 = 9

Answer:

1

Step-by-step explanation:

6

------

2(1+2)

6

-----

2(3)

6

-----

6

1

I don’t understand these 3 questions and I need help.

Answers

Not sure about the first one but the second one is option c (or -3). You just have to factor and find the solutions (so it would be -7 and 4 and then u just add them)

For question 39 the answer is c

Answer:

1: A=1

2: -3

3: C

Step-by-step explanation:

1: If 3x+4 is a factor, then -4/3 is equal to x. Substitute it in for x and solve for a.  This gives us A=1.

For the commenter not understanding how I got -4/3: 3x+4 being a factor means that it equals 0. It might help you understand this if you remember that after factoring, like I did for 38 in my photo, we take expressions like x-4 and set them equal to 0 to get x=4, a solution. So, subtract 4 from both sides to get 3x=-4, then divide both sides by 3 to get x alone. Thus, x=-4/3.

2: To find the sum, we first need to find the two solutions. We can factor to get (x+7)(x-4). This gives us x=-7 and x=+4. The solution of these two would be (-7)+4 is -3.

3: B is a close answer, but the signs are wrong on the bottom. Factoring the question would give us 2(x-2) / 2(x^2-x-2). Factoring that equation is 2(x-2) / 2(x+1)(x-2). Simplifying this gives us 1 / x+1.

Sorry for the bad penmanship, I wanted to make it a little clearer for you! I really hope I helped! :)

Starting with a fresh bar of soap, you weigh the bar each day after you take a shower. Then you find the regression line for predicting weight from number of days elapsed. The slope of this line will be:__________.

Answers

Answer:

The slope will be negative

Step-by-step explanation:

The slope of the regression line tells us about the relationship or behavior of the dependent and independent variables. In the scenario above, where the weight is being compared with the number of days elapsed. What is expected of the weight and quantity of a bar soap each time it is used for a shower is that it will decrease in weight. Therefore, as the number of days increases, and hence, number of showers rise, the weight of soap will decrease. Hence, we'll obtain a negative slope, one in which the increase in a variable leads to decrease in the other.

write your answer in simplest radical form​

Answers

Answer:

s = 17

Step-by-step explanation:

Using the tangent ratio in the right triangle and the exact value

tan60° = [tex]\sqrt{3}[/tex] , then

tan60° = [tex]\frac{opposite}{adjacent}[/tex] = [tex]\frac{17\sqrt{3} }{s}[/tex] = [tex]\sqrt{3}[/tex] ( multiply both sides by s )

s × [tex]\sqrt{3}[/tex] = 17[tex]\sqrt{3}[/tex] ( divide both sides by [tex]\sqrt{3}[/tex] )

s = 17

Last week, you spoke with 800 customers in 40 hours."
Employee: "That is an average of __________ customers every 30 minutes."

Answers

Answer:

10 customers

Step-by-step explanation:

Hi!

Each hour has 60 minutes, so two half hour (30 minute) blocks. Thus, 1 hour = 2 half hours, so 40 hours = 80 half hours.

800 customers in 80 half hours, divide that:

800 customers / 80 half hours = 10 customers / half hour

So, your answer is 10 customers every half hour, or 10 customers every 30 minutes.

Average is [tex]10[/tex] customers per hour

Average is a single number taken as representative of a list of numbers, usually the sum of the numbers divided by how many numbers are in the list.

Total number of customers [tex]=800[/tex]

Total number of hours [tex]=40[/tex]

                                      [tex]=40\times 60[/tex]

                                      [tex]=2400[/tex] minutes

Average (in every [tex]30[/tex] minutes)  [tex]=[/tex] Total number of customers [tex]\div[/tex] Total number of hours

                                                   [tex]=\frac{800}{2400 \div 30}[/tex]

                                                   [tex]=10[/tex] customers per hour

For more information:

https://brainly.com/question/19622178?referrer=searchResults                                                  

               

A well-known brokerage firm executive claimed that 60% of investors are currently confident of meeting their investment goals. An XYZ Investor Optimism Survey, conducted over a two week period, found that in a sample of 100 people, 69% of them said they are confident of meeting their goals. Test the claim that the proportion of people who are confident is larger than 60% at the 0.01 significance level.
The null and alternative hypothesis would be:________
a. H0:μ=0.6H0:μ=0.6
H1:μ≠0.6H1:μ≠0.6
b. H0:μ=0.6H0:μ=0.6
H1:μ<0.6H1:μ<0.6
c. H0:μ=0.6H0:μ=0.6
H1:μ>0.6H1:μ>0.6
d. H0:p=0.6H0:p=0.6
H1:p≠0.6H1:p≠0.6
e. H0:p=0.6H0:p=0.6
H1:p>0.6H1:p>0.6
f. H0:p=0.6H0:p=0.6
H1:p<0.6H1:p<0.6
The test is:________
a. two-tailed
b. left-tailed
c. right-tailed
The test statistic is:_______ (to 3 decimals)
The p-value is:_______ (to 4 decimals)
Based on this we:________
a. Fail to reject the null hypothesis
b. Reject the null hypothesis

Answers

We are testing a hypothesis. So, first we identify the null and the alternative hypothesis, then we find the test statistic, and with the test statistic, the p-value is found.

Null and alternative hypothesis:

Claim the the proportion is of 60%, thus, the null hypothesis is:

[tex]H_0: p = 0.6[/tex]

Test if the proportion is greater than 60%, thus, the alternative hypothesis is:

[tex]H_1: p > 0.6[/tex]

And the answer to the first question is given by option c.

Classification:

We are testing if the proportion is greater than a value, so it is a right-tailed test.

Test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.6 is tested at the null hypothesis:

This means that [tex]\mu = 0.6, \sigma = \sqrt{0.4*0.6}[/tex]

Survey, conducted over a two week period, found that in a sample of 100 people, 69% of them said they are confident of meeting their goals.

This means that [tex]n = 100, X = 0.69[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.69 - 0.6}{\frac{\sqrt{0.4*0.6}}{\sqrt{100}}}[/tex]

[tex]z = 1.837[/tex]

The test statistic is z = 1.837.

p-value:

The p-value of the test is the probability of finding a sample proportion above 0.69, which is 1 subtracted by the p-value of z = 1.837.

Looking at the z-table, z = 1.837 has a p-value of 0.9669.

1 - 0.9669 = 0.0331

The p-value is 0.0331.

Decision:

The p-value of the test is 0.0331 > 0.01, and thus:

a. Fail to reject the null hypothesis

For another example of a problem of a test of hypothesis, you can take a look at:

https://brainly.com/question/24166849

Mathematics question help

Answers

Distance Formula: [tex]\sqrt{(x_{2} - x_{1})^2 + (y_{2} - y_{1})^2}[/tex]

Point 1: (9,0)

Point 2: (5,-8)

D = sqrt[ (5 - 9)^2 + (-8 - 0)^2 ]

D = sqrt[ (-4)^2 + (-8)^2 ]

D = sqrt[ 16 + 64]

D = sqrt(80)

Hope this helps!

Answer:

4 square root of 5

Step-by-step explanation:



welp I am getting graded for this​

Answers

Answer:

it is summer how do y'all still have school,like don't they give y'all a break

The polygons in each pair are similar. Find the missing side length.

Answers

Let missing side be x

If both polygons are similar

[tex]\\ \sf\longmapsto \dfrac{3}{4}=\dfrac{18}{x}[/tex]

[tex]\\ \sf\longmapsto 3x=4(18)[/tex]

[tex]\\ \sf\longmapsto 3x=72[/tex]

[tex]\\ \sf\longmapsto x=\dfrac{72}{3}[/tex]

[tex]\\ \sf\longmapsto x=24[/tex]

Please help me with this on the picture

Answers

9514 1404 393

Answer:

  (-5, 4)

Step-by-step explanation:

The inside corner moves from (2, -2) to (-3, 2). That is 5 is subtracted from the x-coordinate, and 4 is added to the y-coordinate. (x, y) ⇒ (x -5, y +4)

The translation vector can be written horizontally as (-5, 4), or vertically as ...

  [tex]\displaystyle\binom{-5}{4}[/tex]

Complete the table for the given rule.
Rule: y is 0.750.750, point, 75 greater than x
x y
0
3
9

Answers

Answer:

está inglês não dá para entende

a car drives at 45 km/h for 75 minutes how far does the car travel

Answers

Answer:

56.25km

Step-by-step explanation:

75min = 5/4 h

distance = speed * time = 45 * 5/4 = 56.25

factorize : ( p- q ) cube​

Answers

Answer:

[tex]( {p - q}^{3} ) \\ = {p}^{2} - 3 {p}^{2} q + 3p {q}^{2} - {q}^{3} [/tex]

Hope my answer helped u :)

What is an explicit formula for the geometric sequence -64,16,-4,1,... where the first term should be f(1).

Answers

Answer:

[tex]a_{n} = -64(-\frac{1}{4})^{n-1}[/tex]

it seems like the first term is -64, so lets write the formula accordingly:

a_n = a1(r)^(n-1)

where 'n' is the number of terms

a1 is the first term of the sequence

'r' is the ratio

the ratio is [tex]-\frac{1}{4}[/tex] because -64 * [tex]-\frac{1}{4}[/tex] = 16 and so on...

the explicit formula is :

[tex]a_{n}[/tex] = [tex]-64(-\frac{1}{4} )^{n-1}[/tex]

write your answer as an integer or as a decimal rounded to the nearest tenth​

Answers

Answer:

FH ≈ 6.0

Step-by-step explanation:

Using the sine ratio in the right triangle

sin49° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{FH}{FG}[/tex] = [tex]\frac{FH}{8}[/tex] ( multiply both sides by 8 )

8 × sin49° = FH , then

FH ≈ 6.0 ( to the nearest tenth )

Answer:

6

Step-by-step explanation:

sin = opposite/hypotenuse

opposite = sin * hypotenuse

sin (49) = 0,75471

opposite = 0,75471 * 8 = 6,037677 = 6

Algebra word problem plz help me​

Answers

Step-by-step explanation:

here's the answer to your question

Write a simple algorithm to add two numbers

Answers

Answer:

Write an algorithm to add two numbers entered by user. Step 2: Declare variables num1, num2 and sum. Step 3: Read values num1 and num2. Step 4: Add num1 and num2 and assign the result to sum.

Hope it helped . Here is the answer.

Where r is the radius of the cylinder and h is the height of the cylinder.
Find the surface area when r is 7 inches and h is 9 inches.




Sa of cylinder= 2(pi)rh + 2(pi)r squared

Answers

Answer:

703.7 in²

Step-by-step explanation:

SA = 2πrh+2πr²

= 2×π×7×9+2×π×7²

= 224π

= 703.7 in² (rounded to the nearest tenth)

Answer:

224π

in²

Step-by-step explanation:

Write an inequality to describe the region.
The solid cylinder that lies on or below the plane z = 1 and on or above the disk in the xy-plane with center the origin and radius 3

Answers

Answer:

I don't really know

Step-by-step explanation:

Why don't u ask ur teacher for help that will help u more so in a test u can't use brainly

Write each word phrase as an algebrale
expression for exercises 66-69
66) ten less than a number
67) the product of x andy
The algebraic expression for ten less than n

Answers

66) ten less than a number

Let the number be n

= n - 10

67) the product of x and y

= x × y or xy

68) The algebraic expression for ten less than n

= n - 10

Must click thanks and mark brainliest

What is the simplified form of square root 400 x to the power 100

Answers

Step-by-step explanation:

[tex]thank \: you[/tex]

Answer:

20x⁵⁰

Step-by-step explanation:

With the equation √400x¹⁰⁰

we need to take the square root away separately

√400 = √20*20 = 20

Then with x¹⁰⁰

√x¹⁰⁰ = √x⁵⁰*x⁵⁰ = x⁵⁰

So √400x¹⁰⁰ = 20x⁵⁰

hope this helps

Find the 97th term of the arithmetic sequence 17, 26,35,...

Answers

Hy mate!!

The answer of your question is in the attachment..!!

.

.

Hope this answer helps you..!!

.

.

Select it as the BRAINLIEST..!!

Find the greatest rational number r such that the ratios 8/15 ÷ r and 18/35 ÷ r are whole numbers?

Answers

The answer is "[tex]\bold{\frac{2}{105}}[/tex]", and the further calculation can be defined as follows:

When the "r" is the greatest common divisor for the two fractions.

So, we will use Euclid's algorithm:  

[tex]\to \bold{(\frac{8}{15}) -(\frac{188}{35})}\\\\\to \bold{(\frac{8}{15} -\frac{188}{35})}\\\\\to \bold{(\frac{56-54}{105})}\\\\\to \bold{(\frac{2}{105})}\\\\[/tex]

this is  [tex]\bold{(\frac{8}{15}) \ \ mod \ \ (\frac{18}{35})}[/tex]

we can conclude that the GCD for [tex]\bold{\frac{54}{105}}[/tex], when divided by [tex]\bold{\frac{2}{105}}[/tex], will be the remainder is 0.  Rational numbers go from [tex]\bold{\frac{2}{105}}[/tex] with the latter being the highest.

So, the final answer is "[tex]\bold{\frac{2}{105}}[/tex]".

Learn more:

greatest rational number:brainly.com/question/16660879

Which phrase describes an unknown or changeable quality?
3 feet and 7 inches
4 quarts in a gallon
2 o'clock in the afternoon
The height of the building times 1/2

Answers

Answer:

it should be the height of the building time 1/2

Step-by-step explanation:

let me know if its correct or incorrect we'll I hope this help you

Calculate the range and the standard deviation for the set of numbers.
6,5, 1, 5, 8, 5, 3, 5, 4,7
The range is
(Simplify your answer.)

Can I please get help with this problem?

Answers

Answer:

When time is short and you just want a rough estimate of the standard deviation, turn to the range rule to quickly estimate the standard deviation value. The standard deviation is approximately equal to the range of the data divided by 4. That's it, simple.

prove that 2^n+1>(n+2).sin(n)​

Answers

Step-by-step explanation:

F(n)=|sin(n)|+|sin(n+1)|

then

F(n+π)=|sin(n+π)|+|sin(n+π+1)|=|sin(n)|+|sin(n+1)|=F(n)

and

F(π−n)=|sin(π−n)|+|sin(π−n+1)|=|sinn|+|sin(n−1)|≠F(n)

so we must prove when n∈(0,π), have

F(n)>2sin12

when n∈(0,π−1),then

F(n)=sinn+sin(n+1)=sinn(1+cos1)+sin1cosn

and n∈(π−1,π),then

F(n)=sinn−sin(n+1)

How prove it this two case have F(n)>2sin12? Thank you

and I know this well know inequality

|sinx|+|sin(x+1)|+|sin(x−1)|≥2sin1,x∈R

Needddd annnsssweeerrr

Answers

Answer:

90in2

Step-by-step explanation:

3x5x6=90

Answer:

C.90

Step-by-step explanation:

first multiply 3 and 5 which is 15 then times it with 6 which equals 90

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