Rút gọn:

\(\dfrac{2\sqrt{x}+x}{x-4}\)

giải pt

a.\(\sqrt{x}-\sqrt{x\left(x+2\right)}=0\)

 b.\(\sqrt{x^2-1}-\sqrt{x-1}=0\)

\(\sqrt{4x^2}.\sqrt{\dfrac{9}{x^4y^2}}\left(x,y>0\right)\)                 \(\sqrt{a}.\sqrt{2a}.\sqrt{\dfrac{4}{a^4}}\left(a>0\right)\)

Rút gọn:

\(a.\sqrt{x}.\sqrt{\dfrac{1}{x}}\left(x>0\right)b.\sqrt{\dfrac{-1}{y}}.\sqrt{\dfrac{y^3}{-4}}\left(y< 0\right)\)

\(\sqrt{29^2-20^2}\)

\(\left(\sqrt{5}+2\right)\left(\sqrt{5}-1\right)\)

tính:

\(m.\left(\sqrt{6}+2\right)\left(\sqrt{6}-3\right)\)

\(\sqrt{3-\sqrt{2}}.\sqrt{3+\sqrt{2}}\)