简便计算:9999×9999+19999
简便计算如下:=199999+99999×(10000-1)=199999-99999+99999×10000=100000+999990000=1000090000
199999+99999×99999=100000+99999+99999²=99999+1+99999+99999²=99999²+2×99999+1²=(99999+1)²=100000²=10000000000=10^10