Question

(x-5)(x²-9)=0

Answer 1

(1) (x-5)=0 => x=5

(2) (x²-9)=0 => x2=9

x=\(\sqrt{9}\)=3

vậy x=5 và x=9

Answer 2

\(\left(x-5\right)\left(x^2-9\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-5=0\rightarrow x=5\\x^2-9=0\rightarrow x^2=9\rightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\end{matrix}\right.\)

Vậy \(\left[{}\begin{matrix}x=5\\x=3\\x=-3\end{matrix}\right.\)