Question

giải x⁷-14⁵+49x³-36x=0

Answer 1

\(\Leftrightarrow x\left(x^6-14x^4+49x^2-36\right)=0\)

\(\Leftrightarrow x\left(x^2-1\right)\left(x^2-4\right)\left(x^2-9\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x^2=1\\x^2=4\\x^2=9\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=0\\x=\pm1\\x=\pm2\\x=\pm3\end{matrix}\right.\)