a) (2x-1)4 = 16
=> (2x-1)4 = 24 hoặc (-2)4
=>\(\left[{}\begin{matrix}2x-1=2\\2x-1=-2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=2+1\\2x=-2+1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=\dfrac{-1}{2}\end{matrix}\right.\)
b) (2x+1)4 = (2x+1)6
=> (2x+1)4 = (2x+1)4+2
=> (2x+1)4 = (2x+1)4 . (2x+1)2
=> (2x+1)4 - (2x+1)4 . (2x+1)2 = 0
=> (2x+1)4 . [1 - (2x+1)2] = 0
\(\left[{}\begin{matrix}\left(2x+1\right)^4=0\\1-\left(2x+1\right)^2=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x+1=0\\2x+1=1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{-1}{2}\\x=0\end{matrix}\right.\)
(2x-1)^4=16
=>(2x-1)^4=4^4
=>2x-1=4
=> 2x=4+1=5
=>x=5/2=2.5
câu b sai đầu bài ạ sửa lại là (2x+1)4 = (2x+1)6