计算999···9*999···9+1999···9 999···9代表2005个9
问题描述：
计算999···9*999···9+1999···9 999···9代表2005个9
答
结果10000...00000共4010个0999...999*999...999+1999...999=999...999*999...999+1000...000+999...999=999...999（999...999+1）+1000...000=999...999*1000...000+1000...000=1000...000（999...999+1）=1000...0...