Tính: (mathop {lim }limits_{x to – infty } frac{{sqrt {4{x^2} + 1} – 3x}}{{x – 2}}).

(mathop {lim }limits_{x to  – infty } dfrac{{sqrt {4{x^2} + 1}  – 3x}}{{x – 2}} = mathop {lim }limits_{x to  – infty } dfrac{{ – xsqrt {4 + dfrac{1}{{{x^2}}}}  – 3x}}{{xleft( {1 – dfrac{2}{x}} right)}} = mathop {lim }limits_{x to  – infty } dfrac{{ – sqrt {4 + dfrac{1}{{{x^2}}}}  – 3}}{{left( {1 – dfrac{2}{x}} right)}} =  – 5) .

Chọn A.