999...9(1998个9)*999...9(1998个9)+1999...9(1998个9)=?简便计算
问题描述:
999...9(1998个9)*999...9(1998个9)+1999...9(1998个9)=?简便计算
答
999...9(1998个9)*999...9(1998个9)+1999...9(1998个9)=?简便计算