\[1)\ x_{n} = \frac{n - 1}{n}:\]
\[\lim_{x \rightarrow \infty}\frac{n - 1}{n} = \lim_{x \rightarrow \infty}\left( 1 - \frac{1}{n} \right) =\]
\[= 1 - 0 = 1.\]
\[2)\ x_{n} = \frac{2n^{2} - 1}{n^{2}}:\]
\[\lim_{x \rightarrow \infty}\frac{2n^{2} - 1}{n^{2}} = \lim_{x \rightarrow \infty}\left( 2 - \frac{1}{n^{2}} \right) =\]
\[= 2 - 0 = 2.\]
\[3)\ x_{n} = \frac{3n + 4}{n}:\]
\[\lim_{x \rightarrow \infty}\frac{3n + 4}{n} = \lim_{x \rightarrow \infty}\left( 3 + \frac{4}{n} \right) =\]
\[= 3 + 0 = 3.\]
\[4)\ x_{n} = \frac{n - 3}{n + 1}:\]
\[\lim_{x \rightarrow \infty}\frac{n - 3}{n + 1} = \lim_{x \rightarrow \infty}\frac{1 - \frac{3}{n}}{1 + \frac{1}{n}} =\]
\[= \frac{1 - 0}{1 + 0} = 1.\]