\(\frac{3n^{2} - n}{n^{2} - 1} \div \frac{n^{2}}{n + 1}\)
\(\frac{n(3n) - n(1)}{n^{2} + n - n - 1} \div \frac{n^{2}}{n + 1}\)
\(\frac{n(3n - 1)}{n(n) + n(1) - 1(n) - 1(1)} \div \frac{n^{2}}{n + 1}\)
\(\frac{n(3n - 1)}{n(n + 1) - 1(n + 1)} \div \frac{n^{2}}{n + 1}\)
\(\frac{n(3n - 1)}{(n - 1)(n + 1)} \div \frac{n^{2}}{n + 1}\)
\(\frac{n(3n - 1)}{(n - 1)(n + 1)} * \frac{n + 1}{n^{2}}\)
\(\frac{3n - 1}{n - 1} * \frac{1}{n}\)
\(\frac{3n - 1}{n(n - 1)}\)
