a) \(\left(2x-3\right)^4=5^4\)
\(\Rightarrow\left[{}\begin{matrix}2x-3=5\\2x-3=-5\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x=8\\2x=-2\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{8}{2}=4\\x=-\dfrac{2}{2}=-1\end{matrix}\right.\)
b) \(\left(2x-3\right)^3=-64\)
\(\Rightarrow\left(2x-3\right)^3=\left(-4\right)^3\)
\(\Rightarrow2x-3=-4\)
\(\Rightarrow2x=-1\)
\(\Rightarrow x=-\dfrac{1}{2}\)
a/
\(\left(2x-3\right)^4=5^4\\ \Leftrightarrow\left|2x-3\right|=5\\ \Leftrightarrow\left[{}\begin{matrix}2x-3=5\\2x-3=-5\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}2x=8\\2x=-2\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=4\\x=-1\end{matrix}\right.\)
Vậy...
b/ 2x-3=-64
<=>2x = -61
<=> x = -61/2
