Question

(x+5).(x mũ 2-4)=0

 

Answer 1

Trả lời :

\(\left(x+5\right).\left(x^2-4\right)=0\)  

\(\Leftrightarrow\orbr{\begin{cases}x+5=0\\x^2-4=0\end{cases}} \Leftrightarrow\orbr{\begin{cases}x=-5\\x^2=4\end{cases}\Leftrightarrow \orbr{\begin{cases}x=-5\\x=16\end{cases}}}\)

Vậy \(x\in\left\{-5 ; 16\right\}\)

~HT~

Answer 2

Trả lời

\(\left(x+5\right)\left(x^2-4\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x+5=0\\x^2-4=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-5\\x^2=4\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-5\\x^2=\left(\pm2\right)^2\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-5\\x=\pm2\end{cases}}\)

Vậy x = 5; x = 2; x = - 2.