how do u do algebric expressions

Question

doc.brown · Answer

Algebra is another word for fancy adding.
The key is the equal sign and keeping things on either side of it, well... equal.
You can have 2 = 2
and if you add 2 to each side you can think of it two different ways and they are still equal
2+2=4

doc.brown · Answer

The trick with algebra is putting stuff together when you don't know some of the parts, let's say you have some number that you don't know what it is, you can assign it a letter meaning "unknown".  A letter like x for example.
x+2=4

doc.brown · Answer

Whatever you do to one side, you have to do the same to the other or else they are not equal.

doc.brown · Answer

x+2=4
Subtract 2 from each side
x+2$\textbf{-2}$=4$\textbf{-2}$
x+0=2
x=2

You now know what the unknown number x is.  It's 2.
If you double check it with the first equation and replace the x with a 2
x+2=4
$\textbf{2}$+2=4
4=4
It's the same on both sides.

doc.brown · Answer

Am I helping?

anonymous · Answer

ok I need help on a question

doc.brown · Answer

Ok, I'll have a medal for this question.  Close it and post your new question, I will help.

anonymous · Answer

can u help me

doc.brown · Answer

Keep in mind, 2 is not 1+1

2 is +1+1

What you have here is two numbers
-7.2 and the number t

Algebra uses a lot of shortcuts to make math faster. +1 for example can be expressed as just 1 by itself, just to make it easier to write.
$-7.2\times t$ is shortened to $-7.2t$

anonymous · Answer

so -7.2 is the answer

doc.brown · Answer

if you divide -7.2 by -7.2 what do you get?

anonymous · Answer

-1

anonymous · Answer

is -1 correct

doc.brown · Answer

It's positive, 1
negative divided by negative is positive,
do you need me to tell you why?

anonymous · Answer

no thanks can u help me on another problem plz

doc.brown · Answer

$$\frac{-7.2}{-7.2}=1$$

anonymous · Answer

the next problem is n/8=3.4

doc.brown · Answer

$$-7.2t=14.4$$$$\frac{-7.2t}{-7.2}=\frac{14.4}{-7.2}$$$$1t=-2$$$$t=-2$$check$$-7.2t=14.4$$$$-7.2\times-2=14.4$$$$14.4=14.4$$yes it does

doc.brown · Answer

Please post new questions after closing old ones.  It will help both of our SmartScores.

anonymous · Answer

ok but help me with that problem