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3 years ago

PLS HELP ME I NEED ANSWER FAST

Mathematics

2 answers:

erica [24]3 years ago

6 0

Step-by-step explanation:

(4x^3 - 4 + 7x) - ( 2x^3 - x - 8) = 2x^3 + 8x + 4

= (B)

(-3x^2 + x^4 + x) + (2x^4 - 7 + 4x) = 3x^4 - 3x^2 + 5x - 7

= (D)

(x^2 - 2x)(2x + 3) = 2x^3 - x^2 - 6x

= (A)

vaieri [72.5K]3 years ago

4 0

Answer:

it is a.

Step-by-step explanation:

You might be interested in

Find the (a) mean, (b) median, (c) mode, and (d) midrange for the data and then (e) answer the given question. Listed below

mafiozo [28]

Answer:

a) $\bar X = 369.62$

b) $Median=175$

c) $Mode =450$

With a frequency of 4

d) $MidR= \frac{Max +Min}{2}= \frac{49+3000}{2}= 1524.5$

e) $s = 621.76$

And we can find the limits without any outliers using two deviations from the mean and we got:

$\bar X+2\sigma = 369.62 +2*621.76 = 1361$

And for this case we have two values above the upper limit so then we can conclude that 1500 and 3000 are potential outliers for this case

Step-by-step explanation:

We have the following data set given:

49 70 70 70 75 75 85 95 100 125 150 150 175 184 225 225 275 350 400 450 450 450 450 1500 3000

Part a

The mean can be calculated with this formula:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

Replacing we got:

$\bar X = 369.62$

Part b

Since the sample size is n =25 we can calculate the median from the dataset ordered on increasing way. And for this case the median would be the value in the 13th position and we got:

$Median=175$

Part c

The mode is the most repeated value in the sample and for this case is:

$Mode =450$

With a frequency of 4

Part d

The midrange for this case is defined as:

$MidR= \frac{Max +Min}{2}= \frac{49+3000}{2}= 1524.5$

Part e

For this case we can calculate the deviation given by:

$s =\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

And replacing we got:

$s = 621.76$

And we can find the limits without any outliers using two deviations from the mean and we got:

$\bar X+2\sigma = 369.62 +2*621.76 = 1361$

And for this case we have two values above the upper limit so then we can conclude that 1500 and 3000 are potential outliers for this case

5 0

3 years ago

Three teachers handed out math and science textbooks for their classes two teachers had 21 students each and the last teacher ha

Tanya [424]

Answer:

64 textbooks

Step-by-step explanation:

the first two teachers had 21 students each that's 21+21=42

the other teacher had 22 students so apparently all the textbooks handed to the students are,21+21+22=64

8 0

2 years ago

Multiply the polynomials.

Nonamiya [84]

Answer:

The answer to your question is: letter A

Step-by-step explanation:

(x + 3) (3x² + 8x + 9) = 3x³ + 8x² + 9x + 9x² + 24x + 27

= 3x³ + 17x² + 33x + 27 Simplify like terms

Α. 3x3 + 17x2 + 33x + 27

Β. 3x3 + 17x2 – 15x + 27

C. 3x2 + x2 + 33x+ 27

D. 3x3 + 17x2 + 33x - 27

7 0

3 years ago

Can jack built 1/5 of a shed in the same time that kyle can build 5/8 of shed,

Helen [10]

<h3>Answer: 3/10 of a shed</h3>

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

Explanation:

Let's say the shed comes in 40 equal pieces. Each piece takes the same amount of time to assemble. Why am I picking 40? Because 8*5 = 40.

This will allow us to rewrite the fractions with a common denominator.

1/5 = 8/40 .... multiply top and bottom by 8
5/8 = 25/40 .... multiply top and bottom by 5

So Jack can build 8/40 of the shed in the same amount of time Kyle can build 25/40 of the shed.

Instead of writing fractions (which honestly are a pain to deal with), I'm going to write "8 pieces" and "25 pieces" to represent "8/40" and "25/40" respectively. Just keep in mind that there are 40 pieces total.

So again, Jack can assemble 8 pieces in the time it takes Kyle to assemble 25 pieces.

---------------

The ultimate goal is to have Kyle assemble 40 pieces while Jack puts together some unknown number of pieces (some number between 8 and 40). Let's say it's x.

We can then form this proportion

$\frac{\text{Jack's initial 8 pieces}}{\text{x pieces}}=\frac{\text{Kyle's initial 25 pieces}}{\text{goal of 40 pieces}}$

which simplifies or cleans up to

5/x = 25/40

-----------------

Let's solve for x using cross multiplication

8/x = 25/40

8*40 = x*25

320 = 25x

25x = 320

x = 320/25

x = 12.8

So in the time it takes Kyle to assemble all 40 pieces, Jack can put together 12.8 pieces of the shed. However, we can't have Jack put together some fractional piece, because each "piece" is as small as it gets. We can't get any smaller. It would be like saying a fractional part of an atom or a lego block.

So we'll round 12.8 down to 12.

Jack can assemble 12 pieces in the time it takes Kyle to assemble 40 pieces.

Let's then convert this back to fraction form

12 pieces = 12/40 of a shed = 3/10 of a shed.

8 0

3 years ago

aileen and emily are college roommates. working together it takes them 45 minutes to clean their room. today is aileen’s day to

Gre4nikov [31]

The solution for this problem is:

Let time taken by Emily be x

then Aileen take 2/3 of x = 2x/3

1 min work of Emily = 1/x

1 min work of Aileen = 1/ 2x/3 => 3/2x

1 min work of both = 1/45

1/x + 3/2x = 1/45

5/2x = 1/45

1/x = 2/225

Emily take 225/2 mins to complete the work, then Aileen

= 225/2*2/3

= 75 mins.

4 0

3 years ago