# Elementary algebra: solving linear equations in one variable  (Page 3/3)

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Solve for a: $-4a+2-a=3+5a-2$ The solution set is $\left\{\frac{1}{10}\right\}$

## Simplifying expressions first

When solving linear equations the goal is to determine what value, if any, will solve the equation. A general guideline is to use the order of operations to simplify the expressions on both sides first.

Solve for x: $5\left(3x+2\right)-2=-2\left(1-7x\right)$ The solution set is $\left\{-10\right\}$ .

## Conditional equations, identities, and contradictions

There are three different kinds of equations defined as follows.

Conditional Equation
A conditional equation is true for particular values of the variable.
Identity
An identity is an equation that is true for all possible values of the variable. For example, x = x has a solution set consisting of all real numbers, $\Re$ .
A contradiction is an equation that is never true and thus has no solutions. For example, x + 1 = x has no solution. No solution can be expressed as the empty set .

So far we have seen only conditional linear equations which had one value in the solution set. If when solving an equation and the end result is an identity, like say 0 = 0, then any value will solve the equation. If when solving an equation the end result is a contradiction, like say 0 = 1, then there is no solution.

Solve for x: $4\left(x+5\right)+6=2\left(2x+3\right)$ $\begin{array}{cccc}4\left(x+5\right)+6& =& 2\left(2x+3\right)& \mathit{\text{Distribute}}\hfill \\ 4x{+}{20}{+}{6}& =& 4x+6& \mathit{\text{Add same side like terms}}\text{.}\hfill \\ 4x+26& =& 4x+6& \\ 4x+26{-}{4}{x}& =& 4x+6{-}{4}{x}& \mathit{\text{Subtract 4x on both sides.}}\hfill \\ 26& =& 6& \mathit{\text{False}}\hfill \end{array}$ There is no solution, $\varnothing$ .

Solve for y: $3\left(3y+5\right)+5=10\left(y+2\right)-y$ The equation is an identity, the solution set consists of all real numbers, $\Re$ .

## Linear literal equations

Literal equations, or formulas, usually have more than one variable. Since the letters are placeholders for values, the steps for solving them are the same. Use the properties of equality to isolate the indicated variable.

Solve for a: $P=2a+b$ Solution: $a=\frac{P-b}{2}$

Solve for x: $z=\frac{x+y}{2}$ Solution $x=2z-y$

Yes

No

Yes

Yes

No

## Solving in one step

$x=-3$

$y=-5$

$x=\frac{5}{6}$

$x=\frac{5}{6}$

$x=-11$

$a=10$

$y=3$

$x=-\frac{3}{2}$

$t=-3$

$x=-\frac{3}{14}$

## Solve in two steps

$a=10$

$y=5$

$x=0$

$x=\frac{2}{15}$

$y=7$

$x=-\frac{5}{2}$

$a=\frac{1}{8}$

$x=1$

$y=\frac{1}{3}$

$x=-3$

## Solve in multiple steps

$x=-12$

$y=-4$

$a=-\frac{26}{15}$

$x=-1$

No Solution, $\varnothing$

All Reals, $\Re$

$y=\frac{1}{2}$

$x=2$

$a=-\frac{10}{9}$

All Reals, $\Re$

## Literal equations

$w=\frac{P-2l}{2}$

$b=P-a-c$

$C=\frac{5F-160}{9}$

$r=\frac{C}{2\pi }$

$y=-5z+x$

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
how did you get the value of 2000N.What calculations are needed to arrive at it
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