Question

1 (x power 4 + 4 x square - 5)​

Answer 1

x^4-5x^2+4

x^4-4x^2-x^2+4

x^2(x^2-4)-(x^2-4)

(x^2-1)(x^2-4)

Therefore, a^2-b^2 = (a+b) (a-b)

(x^2+1)(x^2-1)(x^2+2)(x^2-2)