Question

(x + 1) (x - 2) (x + 3) (x – 4) – (x2 – x – 7)2

Answer 1

$\left(x+1\right)\left(x-2\right)\left(x+3\right)\left(x-4\right)-\left(x^2-x-7\right)^2\\\\=\left(x+1\right)\left(x-2\right)\left(x+3\right)\left(x-4\right)-\left(x^2-x-7\right)\left(x^2-x-7\right)\\\\=x^4-2x^3-13x^2+14x+24-\left(x^2-x-7\right)\left(x^2-x-7\right)\\\\=x^4-2x^3-13x^2+14x+24-x^4+2x^3+13x^2-14x-49\\\\=-25$