Question

(2-x)\(^3\)=(2-x)\(^5\)Tìm x

Answer 1

\(\left(2-x\right)^3=\left(2-x\right)^5\\ \Rightarrow\left(2-x\right)^3-\left(2-x\right)^5=0\\ \Rightarrow\left(2-x\right)^3\left[1-\left(2-x\right)^2\right]=0\\ \Rightarrow\left[{}\begin{matrix}\left(2-x\right)^3=0\\1-\left(2-x\right)^2=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2-x=0\\\left(2-x\right)^2=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=2\\2-x=\pm1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=2\\x=1\\x=3\end{matrix}\right.\)