数学八年级下册轻巧夺冠50页第25题1/(a-1)+1/(a-1)(a-2)+1/(a-2)(a-3)+1/(a-3)(a-4)+...+1/(a-99)(a-100)
问题描述:
数学八年级下册轻巧夺冠50页第25题
1/(a-1)+1/(a-1)(a-2)+1/(a-2)(a-3)+1/(a-3)(a-4)+...+1/(a-99)(a-100)
答
答案是不是1/(a-1)
你那前面两个数通分就知道了
1/(a-1)+1/(a-1)(a-2)通分以后就变成
(a-2)/(a-1)(a-2)
这样就可以把a-2约掉 这样以此类推
就还剩1/(a-1)