(1+1/3)×(1+1/9)×(1+1/81) 简便计算过程,/是分数线,÷是除号
问题描述:
(1+1/3)×(1+1/9)×(1+1/81) 简便计算过程,/是分数线,÷是除号
答
(1+1/3)(1+1/9)(1+1/81)
=(1-1/3)(1+1/3)(1+1/9)(1+1/81) x3/2
=(1-1/9)(1+1/9)(1+1/81)x3/2
=(1-1/81)(1+1/81) x3/2
=(1-1/6561)x3/2
=6560/6561x3/2
=3280/2187