Question

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

 

Answer 1

`x^2(x^2+4)-x^2-4=0`

`<=>(x^2+4)(x^2-1)=0`

  Mà `x^2+4 > 0`

  `=>x^2-1=0`

`<=>x=+-1`

Answer 2

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

Ta có \(x^2\)+4 > 0 => \(x^2-1=0\)=> (x - 1) (x + 1) = 0

=> x = \(\pm1\)

Answer 3