Bài 1:
\(a,ĐK:-5x\ge0\Leftrightarrow x\le0\\ b,ĐK:2x-3\ge0\Leftrightarrow x\ge\dfrac{3}{2}\)
Bài 2:
\(1,=\sqrt{11\cdot11\cdot5\cdot7\cdot35}=\sqrt{11^2\cdot35^2}=11\cdot35=385\\ 2,\\ a,=\left|2-\sqrt{3}\right|=2-\sqrt{3}\\ b,=2\sqrt{5}-3\sqrt{5}+15\sqrt{2}+6\sqrt{2}\\ =21\sqrt{2}-\sqrt{5}\)
Bài 3:
\(a,Q=\dfrac{x+\sqrt{x}+\sqrt{x}-x}{\left(1-\sqrt{x}\right)\left(1+\sqrt{x}\right)}+\dfrac{\sqrt{x}-3}{1-x}\\ Q=\dfrac{2\sqrt{x}+\sqrt{x}-3}{\left(1-\sqrt{x}\right)\left(1+\sqrt{x}\right)}=\dfrac{3\left(\sqrt{x}-1\right)}{\left(1-\sqrt{x}\right)\left(1+\sqrt{x}\right)}=\dfrac{-3}{\sqrt{x}+1}\\ b,Q=-1\Leftrightarrow\dfrac{3}{\sqrt{x}+1}=1\Leftrightarrow\sqrt{x}+1=3\Leftrightarrow x=4\left(tm\right)\)
