Solving for x in Algebra: Cross Multiplication Method Explained

[Johnnycab]

I was asked to solve for x,
i tried cross multiplying x by 1.5 and 4.8 by 1.5, the moving my 2.18x over to my left side.

(x-4.8)/1.5=2.18x
1.5x-7.2=2.18x
1.5x-2.18x=7.2
-.68x=7.2
-.68/-.68=7.2/.-.68
x=10.5

Did i do this correctly

 

[courtrigrad]

no you did not do it correctly$$\frac{x-4.8}{1.5} = 2.18x$$$$x-4.8 = ?$$
$$x = ?$$

 

[Office_Shredder]

No. (x-4.8)/1.5 does NOT equal 1.5x -7.2

What you would do is multiply both sides by 1.5:

(x-4.8)/1.5=2.18x
1.5*(x-4.8)/1.5=2.18x*1.5
x-4.8=3.27x

 

[L²Cc]

what software do you use?

no you did not do it correctly


$$\frac{x-4.8}{1.5} = 2.18x$$


$$x-4.8 = ?$$



$$x = ?$$

on a slight tangent, what software do you use to type all these mathematical notations. I'm putting together a math portfolio and I'm using word which is not very accurate in terms of mathematical notation...thank you. please reply asap!

 

[courtrigrad]

its called LaTex. you can type it in the forums using [tex ] [/tex ] (with no spaces). You can also download MikTeX if you have Windows to get LaTex.

 

[L²Cc]

oh ok...and can I use latex as an application, as in I can print the doc once I'm done...it is not html?

 

[courtrigrad]

no, its not html. you can print the document once

 

[L²Cc]

oh all right thanks for the fast reply.

 

[Johnnycab]

thanks i see what i didnt do