Question

Tìm x biết (x-2)(x^2+6x+6)=0

Answer 1

\(\left(x-2\right)\left(x^2+6x+6\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x^2+6x+6=0\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=2\\\left(x+3\right)^2=3\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=\sqrt{3}-3\\x=-\sqrt{3}-3\end{matrix}\right.\)

Answer 2

Ta có: \(\left(x-2\right)\left(x^2+6x+6\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x+3-\sqrt{3}\right)\left(x+3+\sqrt{3}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-3+\sqrt{3}\\x=-3-\sqrt{3}\end{matrix}\right.\)