Question

Tim x , biet

(x^2+1).(x^2-4)=0

Answer 1

x^2 +1 =0 hoac x^2 -4 =0

x^2 = -1 (vo ly) hoac X^2 =4

suy ra x=2 hoac x=-2

Answer 2

 x²+1=0 hoặc x²-4=0

x² =-1=> vô lí

 x²-4=0=x^2=4=>x=2 hoặc x=-2

vậy x=2 hoặc -2

 

 

Answer 3

vì (x^2+1).(x^2-4)=0

\(\Rightarrow\)x^2+1=0 hoặc x^4-4=0

     x^2    =-1         x^4    =4

      x^2    =  -1^2      x^4    =  

Answer 4

Ta có: (x²+1)(x²-4)=0
      \(\Rightarrow\)\(\left[{}\begin{matrix}x^2+1=0\\x^2-4=0\end{matrix}\right.\)  \(\Rightarrow\) \(\left[{}\begin{matrix}x^2=-1\\x^2=4\end{matrix}\right.\)

Vậy:   \(\left[{}\begin{matrix}x^2=-1\\x^2=4\end{matrix}\right.\) thì (x²+1)(x²-4)=0