Giải thích các bước giải:
$B=\lim_{x\to\infty}\dfrac{\sqrt{4x^2+12x+3}-\sqrt[3]{27+54x+x^3}}{3x-4}$
$\to B=\lim_{x\to\infty}\dfrac{\sqrt{4+\dfrac{12}{x}+\dfrac{3}{x^2}}-\sqrt[3]{\dfrac{27}{x^3}+\dfrac{54}{x^2}+1}}{3-\dfrac4x}$
$\to B=\dfrac{\sqrt{4+0+0}-\sqrt[3]{0+0+1}}{3-0}$
$\to B=\dfrac{1}{3}$