计算:(1+19/105)+(1+19/105×2)+(1+19/105×3)+…+(1+19/105×20)
问题描述:
计算:(1+
)+(1+19 105
×2)+(1+19 105
×3)+…+(1+19 105
×20) 19 105
答
(1+
)+(1+19 105
×2)+(1+19 105
×3)+…+(1+19 105
×20),19 105
=(1+1+1+…+1)+(1+2+3+…+20)×
,19 105
=20+(1+20)×20×
,19 105
=20+21×20×
,19 105
=20+76,
=96.