怎么配成这样?

2025-02-27 18:02:00
推荐回答(2个)
回答1:

回答2:

x^2-2x-3
=x^2-2x+1+(-3-1)
=(x-1)^2-4
=(x-1+2)(x-1-2)
=(x+1)(x-3)