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2 years ago

What is -2(-y) in expanded form

Mathematics

1 answer:

damaskus [11]2 years ago

4 0

Answer:

Step-by-step explanation:

$(-2)(-y) = (-1)(2)(-1)(y) = (-1)^2\ccdot 2y = 2y$

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What’s the answer need help to get good grade.

disa [49]

Answer:

3 to 7

Step-by-step explanation:

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2 years ago

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Vince has a movie rental gift card that start with $50 on it. Each movie he rents costs him $4.

Leto [7]

Linear function: d = -4m+50 (that's a negative 4 btw)

Slope: -4

y-intercept: 50

I'm truly sorry but I forgot how to do the last one :(

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2 years ago

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Which statement comparing x² + 10 and x + x + x is true when x=−5 ?

Lina20 [59]

X^2 + 10 = 35 when x = -5
x + x + x = 3x = -15 when x = -5.

The answer is B because part A just restates the first equation, and Part C determines which is greater. If you want to determine the difference between the two when x = -5, part B is the best answer because it subtracts the product of one of them from the other.

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3 years ago

Assume you have noted the following prices for books and the number of pages that each book contains. Book Pages (x) Price (y) A

belka [17]

Answer:

a) $y=0.00991 x +1.042$

b) $r^2 = 0.7503^2 = 0.563$

c) $r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

Step-by-step explanation:

Data given

x: 500, 700, 750, 590 , 540, 650, 480

y: 7.00, 7.50 , 9.00, 6.5, 7.50 , 7.0, 4.50

Part a

We want to create a linear model like this :

$y = mx +b$

Wehre

$m=\frac{S_{xy}}{S_{xx}}$

And:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=2595100-\frac{4210^2}{7}=63085.714$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i){n}}=30095-\frac{4210*49}{7}=625$

And the slope would be:

$m=\frac{625}{63085.714}=0.00991$

Nowe we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{4210}{7}=601.429$

$\bar y= \frac{\sum y_i}{n}=\frac{49}{7}=7$

And we can find the intercept using this:

$b=\bar y -m \bar x=7-(0.00991*601.429)=1.042$

And the line would be:

$y=0.00991 x +1.042$

Part b

The correlation coefficient is given by:

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

For our case we have this:

n=7 $\sum x = 4210, \sum y = 49, \sum xy = 30095, \sum x^2 =2595100, \sum y^2 =354$

$r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

The determination coefficient is given by:

$r^2 = 0.7503^2 = 0.563$

Part c

$r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

4 0

3 years ago

A car traveled 330 miles during a 5½ hour period. If the speed at which the car traveled can be represented in the equation d=rt

Alina [70]

Answer:

The car was travelling at a speed of 60 miles per hour.

Step-by-step explanation:

Given:

Distance traveled = 330 miles

Time Period = $5 \frac12\ hr$

we need to find the speed of the car .

Solution:

Time Period = $5 \frac12\ hr$

Now we can say that;

$\frac12\ hr =0.5\ hr$

So Time period = $5+0.5 =5.5\ hr$

Now we know that;

Distance traveled $(d)$ is equal to Speed $(r)$ multiplied by Time Period $(t)$ .

framing in equation form we get;

$d=rt\\\\330 =r\times 5.5$

Dividing both side by 5.5 we get;

$\frac{330}{5.5}=\frac{5.5r}{5.5}\\\\r = 60\ mi/hr$

Hence The car was travelling at a speed of 60 miles per hour.

6 0

3 years ago

What is -2(-y) in expanded form ​

What is -2(-y) in expanded form