Lời giải:
\(\lim\limits_{n\to \infty}\frac{3^n-4.2^{n-1}-3}{3.2^n+4^n}=\lim\limits_{n\to \infty}\frac{3^n-2.2^n-3}{3.2^n+4^n}\)
\(=\lim\limits_{n\to \infty}\frac{(\frac{3}{4})^n-2(\frac{2}{4})^n-\frac{3}{4^n}}{3(\frac{2}{4})^n+1}=\frac{0-2.0-0}{3.0+1}=0\)