Question

这2道分解因式.,1.(x+1)(x+2)(x+3)(x+6)+x^22.1999x^2-(1999^2 -1)x-19

Answer 1

(x+1)(x+2)(x+3)(x+6)+x^2 =(x^2+6x+6)^2

1999x^2-(1999^2 -1)x-1999 =(x-1999)(1999x-1)

(x+y-2xy)(x+y-2)(xy-1)^2已经是最简