# 6.3 Models and applications  (Page 4/9)

 Page 4 / 9

A game room has a perimeter of 70 ft. The length is five more than twice the width. How many ft 2 of new carpeting should be ordered?

250 ft 2

## Solving a volume problem

Find the dimensions of a shipping box given that the length is twice the width, the height is $\text{\hspace{0.17em}}8\text{\hspace{0.17em}}$ inches, and the volume is 1,600 in. 3 .

The formula for the volume of a box is given as $\text{\hspace{0.17em}}V=LWH,$ the product of length, width, and height. We are given that $\text{\hspace{0.17em}}L=2W,$ and $\text{\hspace{0.17em}}H=8.\text{\hspace{0.17em}}$ The volume is $\text{\hspace{0.17em}}1,600\text{\hspace{0.17em}}$ cubic inches.

$\begin{array}{ccc}\hfill V& =& LWH\hfill \\ \hfill 1,600& =& \left(2W\right)W\left(8\right)\hfill \\ \hfill 1,600& =& 16{W}^{2}\hfill \\ \hfill 100& =& {W}^{2}\hfill \\ \hfill 10& =& W\hfill \end{array}$

The dimensions are $\text{\hspace{0.17em}}L=20\text{\hspace{0.17em}}$ in., $\text{\hspace{0.17em}}W=10\text{\hspace{0.17em}}$ in., and $\text{\hspace{0.17em}}H=8\text{\hspace{0.17em}}$ in.

Access these online resources for additional instruction and practice with models and applications of linear equations.

## Key concepts

• A linear equation can be used to solve for an unknown in a number problem. See [link] .
• Applications can be written as mathematical problems by identifying known quantities and assigning a variable to unknown quantities. See [link] .
• There are many known formulas that can be used to solve applications. Distance problems, for example, are solved using the $\text{\hspace{0.17em}}d=rt\text{\hspace{0.17em}}$ formula. See [link] .
• Many geometry problems are solved using the perimeter formula $\text{\hspace{0.17em}}P=2L+2W,$ the area formula $\text{\hspace{0.17em}}A=LW,$ or the volume formula $\text{\hspace{0.17em}}V=LWH.\text{\hspace{0.17em}}$ See [link] , [link] , and [link] .

## Verbal

To set up a model linear equation to fit real-world applications, what should always be the first step?

Answers may vary. Possible answers: We should define in words what our variable is representing. We should declare the variable. A heading.

Use your own words to describe this equation where n is a number:

$5\left(n+3\right)=2n$

If the total amount of money you had to invest was $2,000 and you deposit $\text{\hspace{0.17em}}x\text{\hspace{0.17em}}$ amount in one investment, how can you represent the remaining amount? $2,000-x$ If a man sawed a 10-ft board into two sections and one section was $\text{\hspace{0.17em}}n\text{\hspace{0.17em}}$ ft long, how long would the other section be in terms of $\text{\hspace{0.17em}}n$ ? If Bill was traveling $\text{\hspace{0.17em}}v\text{\hspace{0.17em}}$ mi/h, how would you represent Daemon’s speed if he was traveling 10 mi/h faster? $v+10$ ## Real-world applications For the following exercises, use the information to find a linear algebraic equation model to use to answer the question being asked. Mark and Don are planning to sell each of their marble collections at a garage sale. If Don has 1 more than 3 times the number of marbles Mark has, how many does each boy have to sell if the total number of marbles is 113? Beth and Ann are joking that their combined ages equal Sam’s age. If Beth is twice Ann’s age and Sam is 69 yr old, what are Beth and Ann’s ages? Ann: $\text{\hspace{0.17em}}23;$ Beth: $\text{\hspace{0.17em}}46$ Ben originally filled out 8 more applications than Henry. Then each boy filled out 3 additional applications, bringing the total to 28. How many applications did each boy originally fill out? For the following exercises, use this scenario: Two different telephone carriers offer the following plans that a person is considering. Company A has a monthly fee of$20 and charges of $.05/min for calls. Company B has a monthly fee of$5 and charges \$.10/min for calls.

are nano particles real
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
no can't
Lohitha
where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
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