Question 81345
<pre><font face = "lucida console">
{{{(5x/4)+(1/x)}}} 

I thought the LCD and got

{{{(5x^2)/(4x) + 4/(4x)}}} but don't know where to go from here.

You've done all the hard work.  Now all you need do is 

1. Combine the two numerators, {{{5x^2}}} and {{{4}}} using the same sign " + " 
 (that's between the fractions) between the numerators and get {{{5x^2 + 4}}}.

2. Draw a line underneath the {{{5x^2 + 4}}} and write the LCD, {{{4x}}}, just one time
underneath the line like this:

 {{{(5x^2 + 4)/(4x)}}}

That's all there is to it.

Edwin</pre>