99...9(8个9)*99.9(8个9)+199...9(8个9)的末尾有几个零

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 12:34:42
99...9(8个9)*99.9(8个9)+199...9(8个9)的末尾有几个零

99...9(8个9)*99.9(8个9)+199...9(8个9)的末尾有几个零
99...9(8个9)*99.9(8个9)+199...9(8个9)的末尾有几个零

99...9(8个9)*99.9(8个9)+199...9(8个9)的末尾有几个零
99.9(8个9)*99.9(8个9)+199.9(8个9)
=99.9(8个9)*99.9(8个9)+2×99.9(8个9) +1
=【99.9(8个9)+1】的平方
=100……0(8个0)的平方
=100……0(16个0)
=10的16次方
末尾有16个0

前面是99999998000000001,后面是199999999,即是100000018000000