Question

Factor x4 – 5x2 + 4.

(a2 – 1)(x2 – 4)
(x – 1)(x + 1)(x – 2)(x + 2)
(x2 – 2)(x2 + 2)
(x2 + 2)(x – 1)(x + 1)

Answer 1

this is a quadratic equation of degree 4
u need to split 4 in such a way that u get 5 on adding {or subtracting}