## Elementary Algebra

$\frac{13}{20}n$
We first factor out $n$. Then, to simplify this expression, we find the common denominator (which is the LCM of the denominators of all of the fractions) to obtain: $\frac{3}{5}n-\frac{1}{4}n+\frac{3}{10}n$ =$n(\frac{3}{5}-\frac{1}{4}+\frac{3}{10})$ =$n(\frac{3(4)-1(5)+3(2)}{20})$ =$n(\frac{12-5+6}{20})$ =$n(\frac{7+6}{20})$ =$n(\frac{13}{20})$ =$\frac{13}{20}n$