Решите пожалуйста 1,2,4,5

[latex]1) \lim\limits _{x \to -1} \frac{7x^2+8x+1}{2x+2}= \lim\limits _{x \to -1} \frac{7(x+1)(x+\frac{1}{7})}{2(x+1)}= \lim\limits _{x \to -1} \frac{7x+1}{2}= \frac{-6}{2} =-3\\\\2)\; \; \lim\limits_{x \to 3} \frac{x^2-x-6}{x^2-6x+9}= \lim\limits _{x \to 3} \frac{(x-3)(x+2)}{(x-3)^2}= \lim\limits _{x \to 3} \frac{x+2}{x-3} =\Big [\frac{5}{0}\Big ]=\infty [/latex] [latex]4)\; \; \lim\limits _{x \to 2} \frac{x^2-3x+2}{14-x-3x^2}= \lim\limits _{x \to 3} \frac{5(x-2)(x-1)}{-3(x-2)(x+\frac{7}{3})}=\lim\limits _{x \to 2} \frac{5x-5}{-3x-7}= -\frac{5}{13} [/latex] [latex]5)\; \; \lim\limits _{x \to \infty} \frac{5x^2-x-4}{3x-x^2-2} = \lim\limits _{x \to \infty} \frac{5-\frac{1}{x}-\frac{4}{x^2}}{\frac{3}{x}-1-\frac{2}{x^2}} =\frac{5}{-1}=-5[/latex]