(1+0.3+0.31+0.32……+0.39)×(0.3+0.31+0.32+……+0.39+0.4)-(1+0.3+
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/09/24 06:31:42
(1+0.3+0.31+0.32……+0.39)×(0.3+0.31+0.32+……+0.39+0.4)-(1+0.3+0.31+0.32……+0.39+0.4)×(0.3+0.31+0.32+……+0.39)=
技巧:巧用乘法分配率.
在式子中+0.4×(0.3+0.31+……+0.39+0.4),再-0.4×(0.3+0.31+……+0.39+0.4)
原式=(1+0.3+0.31+0.32……+0.39)×(0.3+0.31+0.32+……+0.39+0.4)+0.4×(0.3+0.31+……+0.39+0.4)-(1+0.3+0.31+0.32……+0.39+0.4)×(0.3+0.31+0.32+……+0.39)-0.4×(0.3+0.31+……+0.39+0.4)
乘法分配率得
原式=(1+0.3+0.31+0.32……+0.39+0.4)×(0.3+0.31+0.32+……+0.39+0.4)-(1+0.3+0.31+0.32……+0.39+0.4)×(0.3+0.31+0.32+……+0.39)-0.4×(0.3+0.31+……+0.39+0.4)
再次运用乘法分配率得
原式=(1+0.3+0.31+0.32……+0.39+0.4)×0.4-0.4×(0.3+0.31+……+0.39+0.4)
再次运用乘法分配率得
原式=1×0.4
=0.4
希望对你解题有所帮助
在式子中+0.4×(0.3+0.31+……+0.39+0.4),再-0.4×(0.3+0.31+……+0.39+0.4)
原式=(1+0.3+0.31+0.32……+0.39)×(0.3+0.31+0.32+……+0.39+0.4)+0.4×(0.3+0.31+……+0.39+0.4)-(1+0.3+0.31+0.32……+0.39+0.4)×(0.3+0.31+0.32+……+0.39)-0.4×(0.3+0.31+……+0.39+0.4)
乘法分配率得
原式=(1+0.3+0.31+0.32……+0.39+0.4)×(0.3+0.31+0.32+……+0.39+0.4)-(1+0.3+0.31+0.32……+0.39+0.4)×(0.3+0.31+0.32+……+0.39)-0.4×(0.3+0.31+……+0.39+0.4)
再次运用乘法分配率得
原式=(1+0.3+0.31+0.32……+0.39+0.4)×0.4-0.4×(0.3+0.31+……+0.39+0.4)
再次运用乘法分配率得
原式=1×0.4
=0.4
希望对你解题有所帮助
(1+0.3+0.31+0.32……+0.39)×(0.3+0.31+0.32+……+0.39+0.4)-(1+0.3+
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