All categories

2 years ago

Can sb explain why there's letters in math...????

1 answer:

5 0

They're called variables (this sounds like vary because the number that a letter could represent varies) so when i say 1 + x = 3 it is saying that they don't know the value of x yet but of course you can solve that by subtracting 1 from 3 which is 2

You might be interested in

Questions 2-7 will all be in regards to this data set:Observation X Y1 20 302 23 353 28 404 26 385 24 376 32 457 35 508 24 349 3

Tomtit [17]

Answer:

r =0.4437

Step-by-step explanation:

We have the follwoing dataset:

X: 20,23,53,4,24,32,35,24,31,23

Y: 30,35,40,38,37,45,50,34,42,32

n=10

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.

And in order to calculate the correlation coefficient we can use this formula:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

For our case we have this:

n=10 $\sum x = 269, \sum y = 383, \sum xy = 10609, \sum x^2 =8645, \sum y^2 =15007$

Th excel figure attached shows the calculations for each sum.

$r=\frac{10(10609)-(269)(383)}{\sqrt{[10(8645) -(269)^2][10(15007) -(383)^2]}}=0.4437$

So then the correlation coefficient would be r =0.4437

3 0

4 years ago

11 identical pairs of Air Jordan cost $660.What is the cost of one pair?

Crank

Answer:

$60

Step-by-step explanation:

11 identical pairs of Air Jordan cost $660.

To find the cost of one pair, you have simply to divide the total amount paid by the total number of pairs.

Total amount paid = $660

Total number of pairs = 11

The cost of one pair $=\$660 : 11=\$60$

6 0

3 years ago

Find the value of x in the equation 3(2x-4)-5(x-2)=1

Lyrx [107]

Answer:

x=3

Step-by-step explanation:

3(2x−4)−5(x−2)=1

Step 1: Simplify both sides of the equation.

3(2x−4)−5(x−2)=1

(3)(2x)+(3)(−4)+(−5)(x)+(−5)(−2)=1(Distribute)

6x+−12+−5x+10=1

(6x+−5x)+(−12+10)=1(Combine Like Terms)

x+−2=1

x−2=1

Step 2: Add 2 to both sides.

x−2+2=1+2

x=3

4 0

3 years ago

Ernesto solves the equation below by first squaring both sides of the equation. \sqrt{\dfrac{1}{2}w+8}=-2 2 1 w+8 =−2square

algol [13]

Answer:

Step-by-step explanation:

Given the equation solved by Ernesto expressed as $\sqrt{\dfrac{1}{2}w+8}=-2$ , the extraneous solution obtained by Ernesto is shown below;

$\sqrt{\dfrac{1}{2}w+8}=-2\\\\square\ both \ sides \ of \ the \ equation\\(\sqrt{\dfrac{1}{2}w+8})^2=(-2)^2\\\\\dfrac{1}{2}w+8 = 4\\\\Subtract \ 8 \ from \ both \ sides\\\\\dfrac{1}{2}w+8 - 8= 4- 8\\\\\dfrac{1}{2}w= -4\\\\multiply \ both \ sides \ by \ 2\\\\\dfrac{1}{2}w*2= -4*2\\\\w = -8$

Hence, the extraneous solution that Ernesto obtained is w = -8

4 0

3 years ago

1. ARCHAEOLOGY While digging a hole to plant a tree,

klio [65]

2(pi)r

2(pi)0.75
Circumference is 4.71.

7 0

2 years ago