\[1)\ \lim_{x \rightarrow 0}\frac{2 + x - x^{3}}{1 + 3x + x^{2}} =\]
\[= \frac{2 + 0 - 0}{1 + 0 + 0} = \frac{2}{1} = 2;\]
\[2)\ \lim_{x \rightarrow \infty}\frac{7x^{3} + 3x^{2} + 1}{14x^{3} - x^{2} - 5} =\]
\[= \lim_{x \rightarrow \infty}\frac{7 + \frac{3}{x} + \frac{1}{x^{2}}}{14 - \frac{1}{x} - \frac{5}{x^{2}}} = \frac{7}{14} = \frac{1}{2}.\]