Đáp án:
a) $-4$
b) $-\dfrac13$
c) $-\dfrac53$
Giải thích các bước giải:
a) $\lim\dfrac{8n-2}{3-2n}$
$=\lim\dfrac{8 -\dfrac2n}{\dfrac3n -2}$
$=\dfrac{8 -0}{0-2}$
$= -4$
b) $\lim\dfrac{\sqrt{n^2 - 4n +2}}{2-3n}$
$=\lim\dfrac{\sqrt{1-\dfrac4n +\dfrac{2}{n^2}}}{\dfrac2n -3}$
$=\dfrac{\sqrt{1 - 0 +0}}{0 -3}$
$=-\dfrac13$
c) $\lim\dfrac{2^n - 5^{n+1}}{3.5^n + 3^n}$
$=\lim\dfrac{2^n - 5.5^{n}}{3.5^n + 3^n}$
$=\lim\dfrac{\left(\dfrac25\right)^n - 5}{3 + \left(\dfrac35\right)^n}$
$=\dfrac{0 -5}{3 +0}$
$= -\dfrac53$
