Lời giải:
\(\lim\limits_{x\to 1}\frac{x-1}{(x^2+3x-2)\sqrt{x+3}-4}=\lim\limits_{x\to 1}\frac{x-1}{(x^2+3x-4)\sqrt{x+3}+2(\sqrt{x+3}-2)}=\lim\limits_{x\to 1}\frac{x-1}{(x-1)(x+4)\sqrt{x+3}+2.\frac{x-1}{\sqrt{x+3}+2}}
\)
\(=\lim\limits_{x\to 1}\frac{1}{(x+4)\sqrt{x+3}+\frac{2}{\sqrt{x+3}+2}}=\frac{2}{21}\)