\(\sqrt{10-x}=2\)

\(\Leftrightarrow\sqrt{\left(10-x\right)^2}=2\)

\(\Leftrightarrow10-x=2\)

\(\Leftrightarrow x=8\)

\(\sqrt{x-5}=3\)

\(\Leftrightarrow\sqrt{\left(x-5\right)}^2=3\)

\(\Leftrightarrow|x-5|=3\)

\(\Leftrightarrow x-5=3\)

\(\Leftrightarrow x=8\)

Rút gọn

A=\(\left(\dfrac{5\sqrt{x}-6}{x-9}-\dfrac{2}{\sqrt{x}-3}\right):\left(1+\dfrac{6}{x-9}\right)\)

Rút gọn 

A=\(\left(\dfrac{4x}{\sqrt{x}-1}-\dfrac{\sqrt{x}-2}{x-3\sqrt{x}+2}\right)\dfrac{\sqrt{x}-1}{x^2}\)