Answer:
Work shown below!
Step-by-step explanation:
[tex]x^{4}-5x^{2} +4[/tex] = [tex]0[/tex]
[tex]A[/tex] = [tex]x^{2}[/tex]
[tex]A^{2} -5A+4[/tex] = [tex]0[/tex]
[tex](A-1)(A-4)[/tex] = [tex]0[/tex]
[tex](x^{2}-1)(x^{2} -4) =0\\(x-1)(x+1)(x-2)(x+2)=0[/tex]
x - 1 = 0
Add 1 to both sides;
x = 1
x + 1 = 0
Subtract 1 from both sides;
x = -1
x - 2 = 0
Add 2 to both sides;
x = 2
x + 2 = 0
Subtract 2 from both sides;
x = -2