Question 48182
{{{(4/3n)+(3/(n+1))+(2/(n^2+n))}}} 
The first thing to realize is the common denominator factor everything you can in the donominators will make the common denominator more obvious... which is 
3*n*(n+1)
Multiplying the top and bottom by the common denominator yields

{{{(4*(n+1))/(3*n*(n+1))+(3*3n/3n*(n+1)) + (2*3/(3n*(n+1)))}}}
{{{(4n +4 +9n +6)/(3*n*(n+1))}}}
{{{(13n+10)/(3*n*(n+1))}}}

I hope that this help you