Question

(x-1)(x-3)(x+1)(x+3)-20 因式分解

Answer 1

(x-1)(x-3)(x+1)(x+3)-20

=(x^2-1)(x^2-9)-20

=x^4-10x^2-11

=(x^2-11)(x^2+1)

=(x-√11)(x+√11)(x^2+1)