a) \(\left(x-1\right)^5=-243\)
\(\Rightarrow\left(x-1\right)^5=\left(-3\right)^5\)
\(\Rightarrow x-1=-3\)
\(\Rightarrow x=\left(-3\right)+1\)
\(\Rightarrow x=-2\)
Vậy \(x=-2.\)
b) \(\left|5x-3\right|-2x=14\)
\(\Rightarrow\left|5x-3\right|=14+2x.\)
\(\Rightarrow\left[{}\begin{matrix}5x-3=14+2x\\5x-3=-14-2x\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}5x-2x=14+3\\5x+2x=-14+3\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}3x=17\\7x=-11\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=17:3\\x=\left(-11\right):7\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{17}{3}\\x=-\frac{11}{7}\end{matrix}\right.\)
Vậy \(x\in\left\{\frac{17}{3};-\frac{11}{7}\right\}.\)
Chúc bạn học tốt!
