\(\sqrt{4x-20}-3\sqrt{\frac{x-5}{9}}=\sqrt{1-x}\left(đk:...\right)\)(tự tìm đk đi)
\(< =>\sqrt{4\left(x-5\right)}-\sqrt{9}.\sqrt{\frac{x-5}{9}}=\sqrt{1-x}\)
\(< =>\sqrt{4}.\sqrt{x-5}-\sqrt{\frac{9\left(x-5\right)}{9}}=\sqrt{1-x}\)
\(< =>2\sqrt{x-5}-\sqrt{x-5}=\sqrt{1-x}\)
\(< =>\sqrt{x-5}.\left(2-1\right)=\sqrt{1-x}\)
\(< =>\sqrt{x-5}=\sqrt{1-x}< =>x-5=1-x\)
\(< =>x+x=1+5< =>2x=6< =>x=3\)(đối chiếu đk)