Question

Tìm x bt:   \(\left(x-3\right)^5=4\left(x-3\right)^3\)

HELP ME!

Answer 1

`#3107`

`(x - 3)^5 = 4(x - 3)^3`

`=> (x - 3)^5 - 4(x - 3)^3 = 0`

`=> (x - 3)^3 * [ (x - 3)^2 - 4] = 0`

`=>`\(\left[{}\begin{matrix}\left(x-3\right)^3=0\\\left(x-3\right)^2-4=0\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x-3=0\\\left(x-3\right)^2=4\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=3\\\left(x-3\right)^2=\left(\pm2\right)^2\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=3\\x-3=2\\x-3=-2\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=3\\x=5\\x=1\end{matrix}\right.\)

Vậy, `x \in {1; 3; 5}.`