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999...9(1998个9)*999...9(1998个9)+1999...9(1998个9)=?简便计算

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/04/29 10:32:44
999...9(1998个9)*999...9(1998个9)+1999...9(1998个9)=?简便计算
原式=999...9(1998个9)*999...9(1998个9)+1999...9(1998个9)
=999...9(1998个9)*(1000...0(1998个0)-1)+1000...0(1998个0)+999...9(1998个9)
=999...9000..0(1998个9接1998个0)-999...9(1998个9)+1000...0(1998个0)+999...9(1998个9)
=999...9000..0(1998个9接1998个0)+1000...0(1998个0)
=1000...0(1998x2个0)
=1000...0(3996个0)