Question

Tìm x:h,\(\sqrt{x+1}+\sqrt{x+6}=5\)

Answer 1

ĐKXĐ : \(x\ge-1\)

\(\sqrt{x+1}+\sqrt{x+6}=5\)  \(\Leftrightarrow\sqrt{x+1}-2+\sqrt{x+6}-3=0\)

\(\Leftrightarrow\dfrac{x-3}{\sqrt{x+1}+2}+\dfrac{x-3}{\sqrt{x+6}+3}=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=3\\\dfrac{1}{\sqrt{x+1}+2}+\dfrac{1}{\sqrt{x+6}+3}=0\left(PTVN\right)\end{matrix}\right.\)

Vậy ... 

Answer 2

Thanks