Trả lời:
\(B=\left(\frac{\sqrt{x}}{\sqrt{x}+4}+\frac{4}{\sqrt{x}-4}\right):\frac{x+16}{\sqrt{x}+2}\left(ĐK:x\ge0;x\ne16\right)\)
\(=\frac{\sqrt{x}\left(\sqrt{x}-4\right)+4\left(\sqrt{x}+4\right)}{\left(\sqrt{x}+4\right)\left(\sqrt{x}-4\right)}\cdot\frac{\sqrt{x}+2}{x+16}\)
\(=\frac{x-4\sqrt{x}+4\sqrt{x}+16}{\left(\sqrt{x}+4\right)\left(\sqrt{x}-4\right)}\cdot\frac{\sqrt{x}+2}{x+16}\)
\(=\frac{x+16}{\left(\sqrt{x}+4\right)\left(\sqrt{x}-4\right)}\cdot\frac{\sqrt{x}+2}{x+16}=\frac{\sqrt{x}+2}{x-16}\)