Question 283977
For this problem:

{{{(5x-15)/(x)}}}divided by{{{(x-3)/(x^3)}}}

You cannot divide the two fractions, you have to multiply the reciprocal (flip)  the 2nd equation :

{{{(5x-15)/(x)}}} multiplied by {{{(x^3)/(x-3)}}}

Now you can simplify these fractions, if you notice 5x-15 can be simplified by taking a 5 out of the equation, both terms are a factor of 5:
{{{5x-15}}}
{{{5(x-3)}}}  
This step is like going backwards, if that's clear.

Now your problem looks like this:

{{{5(x-3)/(x)}}}multiplied by {{{(x^3)/(x-3)}}} 

If you notice, you have two terms that exact, which you can cross out:

{{{5*cross(x-3)/(x)}}}multiplied by {{{(x^3)/cross(x-3)}}}

Next notice the x's, you can subtract one from the other:
{{{5/cross(x)}}}multiplied by {{{(x^3)/(1)}}}
{{{x^3 - x = x^2}}}

After that step:

{{{(5/1)}}}multiplied by {{{(x^2)/1}}}
{{{5x^2}}}