(l-1/2-1/3-1/4-1/5)(1/2+1/3+1/4+1/5+1/6)一(l-1/2-

Question

/3-1/4-1/5-1/6)(1/2+1/3+1/4+1/5)怎么算

Answer 1

设（1-1/2-1/3-1/4-1/5）为a，（1/2+1/3+1/4+1/5）为b，代入得转化为a(b+1/6）-(a-1/6)b,得到ab+1/6a-ab+1/6b，化简为1/6（a+b)，再重新代入，解得1/6（1-1/2-1/3-1/4-1/5+1/2+1/3+1/4+1/5）=1/6*1=1/6

Answer 2

答：
设a=1/2+1/3+1/4+1/5+1/6
原式
=(l-1/2-1/3-1/4-1/5)(1/2+1/3+1/4+1/5+1/6)一(l-1/2-1/3-1/4-1/5-1/6)(1/2+1/3+1/4+1/5)
=[1-(a-1/6)]*a-(1-a)(a-1/6)
=(7/6-a)a+(a-1)(a-1/6)
=7a/6-a^2+a^2-7a/6+1/6
=1/6

Answer 3

追答

完整的过程以给，有图，还有疑问吗？没有就好评吧，话说我是第一个回答的