X^3-21X+20因式分解

2025-05-21 00:41:31
推荐回答(1个)
回答1:

X^3-21X+20
=x^3-x^2+x^2-21x+20
=x^2(x-1)+(x-1)(x-20)
=(x-1)(x^2+x-20)
=(x-1)(x+5)(x-4)