用简便算法解这道题

显示全部楼层 · 2008-2-7 20:35:17

原式＝《7380的平方－（7380＋1）＊（7380－1）》/5/5/5＝（7380的平方－7380的平方＋1）/75＝1/75打的字看起来多，你照着写下来就两个步骤

千问 · 2008-2-7 20:35:17

（7380^2－7381×7379）÷5÷5÷5＝[7380^2－（7380＋1）×（7380－1）]÷（5×5×5）＝[7380^2－（7380^2－1）]÷125＝（7380^2－7380^2＋1）÷125＝1÷125＝0.008

千问 · 2008-2-7 20:35:17

(7380^-7381*7379)/5/5/5=(7380^2-(7380+1)*(7380-1))/5/5/5 =(7380^2-7280^2+1)/125 ＝0.008

千问 · 2008-2-7 20:35:17

(7380^-7381*7379)/5/5/5 =(7380^2-(7380+1)*(7380-1))/5/5/5 =(7380^2-7280^2+1)/125 ＝0.008

千问 · 2008-2-7 20:35:17

(7380的平方-7381*7379)/5/5/5=[(7380的平方-(7380+1)*(7380-1)]/5/5/5 =(7380^2-7280^2+1)/5/5/5=0.008