Answer
$\frac{-2n+16}{n(n+4)}$
Work Step by Step
By inspection, we see that the LCM of the denominators is $n(n+4)$. Therefore, we create a common denominator using this LCM and obtain:
$\frac{4}{n}-\frac{6}{n+4}$
=$\frac{4(n+4)-6(n)}{n(n+4)}$
=$\frac{4n-6n+16}{n(n+4)}$
=$\frac{-2n+16}{n(n+4)}$
