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3 years ago

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You have a total of 21 pens and pencils on your desk. You have 3 more pens than pencils. Write a system linear equations that re

present this situation. How many of each do you have?

1 answer:

labwork [276]3 years ago

4 0

Answer:

x + y = 21x - y = 3

Step-by-step explanation:

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The length of a rectangle is increasing at a rate of 6 cm/s and its width is increasing at a rate of 5 cm/s. When

atroni [7]

Answer:

The area of the rectangle is increasing at a rate of 84 square centimeters per second.

Step-by-step explanation:

The area for a rectangle is given by the formula:

$A=w\ell$

Where <em>w</em> is the width and <em>l</em> is the length.

We are given that the length of the rectangle is increasing at a rate of 6 cm/s and that the width is increasing at a rate of 5 cm/s. In other words, dl/dt = 6 and dw/dt = 5.

First, differentiate the equation with respect to <em>t</em>, where <em>w</em> and <em>l</em> are both functions of <em>t: </em>

$\displaystyle \frac{dA}{dt}=\frac{d}{dt}\left[w\ell]$

By the Product Rule:

$\displaystyle \frac{dA}{dt}=\frac{dw}{dt}\ell +\frac{d\ell}{dt}w$

Since we know that dl/dt = 6 and that dw/dt = 5:

$\displaystyle \frac{dA}{dt}=5\ell + 6w$

We want to find the rate at which the area is increasing when the length is 12 cm and the width is 4 cm. Substitute:

$\displaystyle \frac{dA}{dt}=5(12)+6(4)=84\text{ cm}^2\text{/s}$

The area of the rectangle is increasing at a rate of 84 square centimeters per second.

8 0

3 years ago

Please help me with this problem

inn [45]

Answer: Option 1

<u>Step-by-step explanation:</u>

$\begin {array}{l|c|c||l}&\underline{\quad Length\quad}&\underline{\quad Width\quad}&\underline{\qquad Area\qquad}\\ Current&3x&x&3x\cdot x=3x^2\\Option\ 1\ (triple)&3(3x)=9x&3(x)=3x&9x\cdot 3x=27x^2\\Option\ 2\ (3\ closets)&3x&x&3(3x\cdot x)=9x^2\\\end{array}$

Option 1 has a greater area than option 2.

4 0

3 years ago

Read 2 more answers

4(x-3)-(2x+5)=-3x-27

Georgia [21]

4(x-3)-(2x+5)=-3x-27
4*x - 4*3 - 2x - 5 = -3x - 27
4x - 12 - 2x - 5 = -3x - 27
2x - 17 = -3x - 27
2x + 3x = -27 + 17
5x = -10 / : 5
x = -2

7 0

3 years ago

Read 2 more answers

A shelter in the city house birds and dogs . There are 25% more dogs then birds. If there are 50 birds how many dogs are there?

AfilCa [17]

Answer:

They have 83 dogs and 50 birds.

There are 133 animals in total in the shelter.

Step-by-step explanation:

So let's call the dogs D and the birds B.

D = 25% + B

What ever the amount of animals, the total for D must always be 25% more than B.

To get 100% of the animals, B must equal 37.5% and D must equal 62.5%.

The way I worked this out was:

100% - 25%= 75%

75% divided by 2= 37.5%

37.5% + 25%= 62.5%

And just to check

37.5% + 62.5% = 100%

So to work out 100%:

37.5% = 50

divide both by 37.5 to get 1%

1% = 1.333333

time both by 62.5 to get 62.5%

62.5% = 83.333313

We'll round that answer because I'm pretty sure they don't have a .333313th of a dog.

So D = 62.5% = 83

They have 83 dogs and 50 birds.

Phew! That was the hard part. Now onto something wayyy easier.

To get the total number of animals in the shelter we just do 83 + 50, which is 133.

There are 133 animals in total in the shelter.

Hope this helps you :)

7 0

2 years ago

I NEED HHELP ASAP STOP SENDING ME LINK

Ymorist [56]

Answer:

The answer is B

Step-by-step explanation:

hope that helps

5 0

3 years ago

Read 2 more answers