Question

giúp em nhanh với ạ em cảm ơn

Answer 1

\(\sqrt{5-x}-x=1\left(đk:5\ge x\ge-1\right)\)

\(\Leftrightarrow\sqrt{5-x}=x+1\)

\(\Leftrightarrow5-x=x^2+2x+1\)

\(\Leftrightarrow x^2+3x-4=0\)

\(\Leftrightarrow\left(x-1\right)\left(x+4\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=1\left(tm\right)\\x=-4\left(ktm\right)\end{matrix}\right.\)