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2 years ago

Help me ASAP!!! (64 ÷ -4) ÷ (-2)

1 answer:

5 0

Just do PEMDAS

$parentheses \\ exponents \\ multiplication \\ division \\ addition \\ subtraction$

In this problem we're using: $parentheses$ and $division$

So, ( $64$ ÷ -4) ÷ (- $2$ )
$\frac{64}{-4} = -16$
Problem becomes: $\frac{-16}{-2}$
Answer: $8$

good luck on your assignment and enjoy your day!

~ $MeIsKaitlyn :)$

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In the ordered pair (-12,-6) what is the x-coordinate?

tiny-mole [99]

Answer:

Step-by-step explanation:

The x coordinate would be (-16,-8) I have had this question before hope it helps! ;)

3 0

2 years ago

Read 2 more answers

A political scientist wants to know how college students feel about the Social Security system. She obtains a list of the 3456 u

Marina CMI [18]

Answer:

For this case the population is described as:

All the college students

And the political have a list of 3456 undergraduates at her college for the sampling frame.

The sample would be the 104 students who return the survey.

Is important to notice that since he know the information about her college she can apply inference about the parameter of interest just at her college and not about all the possible students of college.

Step-by-step explanation:

For this case the population is described as:

All the college students

And the political have a list of 3456 undergraduates at her college for the sampling frame.

The sample would be the 104 students who return the survey.

For this case we can also find the non reponse rate since we know that the total of questionnaires are 250 and she got back just 104 answered

$Non-resp. = \frac{250-104}{250} = \frac{146}{250}= 0.584$

So we have a non response rate of 58.4 %

4 0

3 years ago

A number is called evil if it has 666 in it. How many 7 digit numbers are evil?

defon

Step-by-step explanation:

There are 5 different positions of 666:

666////

/666///

//666//

///666/

////666

The forward dashes represent any number from 0 to 9.

Case 1: "666////"

Number of ways = 10⁴ = 10,000.

Case 2: The other positions.

Since the 1st forward dash cannot be 0 (leading digit),

Number of ways for each position = 9 * 10³ = 9,000

Number of ways for all 4 positions = 9,000 * 4 = 36,000.

Total evil numbers = 10,000 + 36,000 = 46,000.

5 0

2 years ago

A metal cylinder can with an open top and closed bottom is to have volume 4 cubic feet. Approximate the dimensions that require

Aleksandr-060686 [28]

Answer:

$r\approx 1.084\ feet$

$h\approx 1.084\ feet$

$\displaystyle A=11.07\ ft^2$

Step-by-step explanation:

<u>Optimizing With Derivatives </u>

The procedure to optimize a function (find its maximum or minimum) consists in :

Produce a function which depends on only one variable
Compute the first derivative and set it equal to 0
Find the values for the variable, called critical points
Compute the second derivative
Evaluate the second derivative in the critical points. If it results positive, the critical point is a minimum, if it's negative, the critical point is a maximum

We know a cylinder has a volume of 4 $ft^3$ . The volume of a cylinder is given by

$\displaystyle V=\pi r^2h$

Equating it to 4

$\displaystyle \pi r^2h=4$

Let's solve for h

$\displaystyle h=\frac{4}{\pi r^2}$

A cylinder with an open-top has only one circle as the shape of the lid and has a lateral area computed as a rectangle of height h and base equal to the length of a circle. Thus, the total area of the material to make the cylinder is

$\displaystyle A=\pi r^2+2\pi rh$

Replacing the formula of h

$\displaystyle A=\pi r^2+2\pi r \left (\frac{4}{\pi r^2}\right )$

Simplifying

$\displaystyle A=\pi r^2+\frac{8}{r}$

We have the function of the area in terms of one variable. Now we compute the first derivative and equal it to zero

$\displaystyle A'=2\pi r-\frac{8}{r^2}=0$

Rearranging

$\displaystyle 2\pi r=\frac{8}{r^2}$

Solving for r

$\displaystyle r^3=\frac{4}{\pi }$

$\displaystyle r=\sqrt[3]{\frac{4}{\pi }}\approx 1.084\ feet$

Computing h

$\displaystyle h=\frac{4}{\pi \ r^2}\approx 1.084\ feet$

We can see the height and the radius are of the same size. We check if the critical point is a maximum or a minimum by computing the second derivative

$\displaystyle A''=2\pi+\frac{16}{r^3}$