Question

4-x/5=-5/4-x

Answer 1

\(\dfrac{4-x}{5}=\dfrac{5}{4-x}\left(ĐK:x\ne4\right)\\ \Leftrightarrow\left(4-x\right)^2=5^2\\ \Leftrightarrow\left[{}\begin{matrix}4-x=5\\4-x=-5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\left(nhận\right)\\x=9\left(nhận\right)\end{matrix}\right.\)