Respuesta :
[tex]\sf \longmapsto \: x^4 + 3x^2 - 4 = 0[/tex]
- Factor left side of equation
[tex]\sf \longmapsto(x+1)(x−1)(x^2+4)=0[/tex]
- Set factors equal to 0
[tex]\sf \longmapsto \: x+1=0 or x−1=0 \: or \: x {}^{2} +4=0[/tex]
- We have two possible solutions
[tex]\sf \longmapsto \: x = - 1[/tex]
OR
[tex]\sf \longmapsto \: x = 1[/tex]