小学数学,递等式100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+……+0.4+0.3-0.2-0.1=
2019-05-30
小学数学,递等式
100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+……+0.4+0.3-0.2-0.1=
优质解答
(100-99.8)+(99.9-99.7)+(99.6-99.4)+.+(0.3-0.1)
=0.2*250
=50
(100-99.8)+(99.9-99.7)+(99.6-99.4)+.+(0.3-0.1)
=0.2*250
=50