Bài 1:
1) \(=\dfrac{-\sqrt{3}\left(1-\sqrt{3}\right)}{1-\sqrt{3}}+\dfrac{\sqrt{5}\left(\sqrt{3}+1\right)}{\sqrt{3}+1}\)
\(=-\sqrt{3}+\sqrt{5}\)
2) \(=\dfrac{\sqrt{3}\left(\sqrt{5}-2\right)}{\sqrt{5}-2}-\dfrac{\sqrt{12}\left(\sqrt{3}+\sqrt{2}\right)}{\sqrt{3}+\sqrt{2}}\)
\(=\sqrt{3}-\sqrt{12}=\sqrt{3}-2\sqrt{3}=-\sqrt{3}\)
Bài 2:
1) ĐKXĐ: \(x\ge-1\)
\(\Leftrightarrow5\sqrt{x+1}-4\sqrt{x+1}+2\sqrt{x+1}=12\)
\(\Leftrightarrow3\sqrt{x+1}=12\Leftrightarrow\sqrt{x+1}=4\)
\(\Leftrightarrow x+1=16\Leftrightarrow x=15\left(tm\right)\)
2) ĐKXĐ: \(x\ge3\)
\(\Leftrightarrow\sqrt{x-3}=5\)
\(\Leftrightarrow x-3=25\Leftrightarrow x=28\left(tm\right)\)