8:
a: \(x^3=27\)
=>\(x^3=3^3\)
=>x=3
b: \(\left(2x-1\right)^3=27\)
=>2x-1=3
=>2x=4
=>x=2
c: \(\left(x-2\right)^2=16\)
=>\(\left[{}\begin{matrix}x-2=4\\x-2=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-2\end{matrix}\right.\)
d: (2x-3)2=9
=>\(\left[{}\begin{matrix}2x-3=3\\2x-3=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=6\\2x=0\end{matrix}\right.\)
=>x=3 hoặc x=0
e: \(2x+5=3^4:3^2\)
=>\(2x+5=3^2=9\)
=>2x=4
=>x=2
f: \(\left(3x-2^4\right)\cdot7^3=2\cdot7^4\)
=>\(\left(3x-16\right)=2\cdot\dfrac{7^4}{7^3}=2\cdot7=14\)
=>3x=30
=>x=10
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