作业帮因式分解(a^2-a-1)(a^2-a-2)-20
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/07 09:53:22
因式分解(a^2-a-1)(a^2-a-2)-20
因式分解(a^2-a-1)(a^2-a-2)-20
因式分解(a^2-a-1)(a^2-a-2)-20
(a^2-a-1)(a^2-a-2)-20
=(a²-a)²-2(a²-a)-(a²-a)+2-20
=(a²-a)²-3(a²-a)-18
=(a²-a-6)(a²-a+3)
=(a+2)(a-3)(a²-a+3)
令a^2-a = k
(a^2-a-1)(a^2-a-2)-20
= (k-1 ) (k-2) -20
= k ² -3k +2 -20
= k² -3k -18
= ( k-6) ( k+3)
= ( a^2-a -6) (a^2-a+3)
= (a-3) (a+2) (a^2-a+3)
施主，我看你骨骼...
全部展开
令a^2-a = k
(a^2-a-1)(a^2-a-2)-20
= (k-1 ) (k-2) -20
= k ² -3k +2 -20
= k² -3k -18
= ( k-6) ( k+3)
= ( a^2-a -6) (a^2-a+3)
= (a-3) (a+2) (a^2-a+3)
施主，我看你骨骼清奇，
器宇轩昂,且有慧根,
乃是万中无一的武林奇才.
潜心修习,将来必成大器，
鄙人有个小小的考验请点击在下答案旁的
"选为满意答案"
收起
设t=a²-a
(a^2-a-1)(a^2-a-2)-20
=(t-1)(t-2)-20
=t²-3t+2-20
=t²-3t-18
=(t-6)(t+3)
=(a²-a-6)(a²-a+3)
=(a-3)(a+2)(a²-a+3)
泪笑为您解答，
如若满...
全部展开
设t=a²-a
(a^2-a-1)(a^2-a-2)-20
=(t-1)(t-2)-20
=t²-3t+2-20
=t²-3t-18
=(t-6)(t+3)
=(a²-a-6)(a²-a+3)
=(a-3)(a+2)(a²-a+3)
泪笑为您解答，
如若满意,请点击[采纳为满意回答];如若您有不满意之处,请指出,我一定改正!
希望还您一个正确答复!
祝您学业进步!
收起