Which of the following polynomials below is identical to the polynomial (x2−1)(x2−4)?
(x2+x−2)(x2−x−2)
(x2−1)(x2−4)=(x2−12)(x2−22)
= (x+1)(x–1)(x–2)(x–2)
And (x2+x−2)(x2−x−2)
=(x2+2x−x−2)(x2−2x+x−2)
= (x(x+2)−1(x+2))(x(x–2)+1(x–2))
= (x–1)(x+2)(x+1)(x–2)