1999+999*999的简便计算

问题描述:

1999+999*999的简便计算

1999+999*999
=2000+999^2-1
=2000+(999+1)(999-1)
=2000+998000
=1000000

2000-1+(1000-1)*(1000-1)
=2000-1+1000*1000-2*1000*1+1
=1000*1000

1999+999×999
=1000+999+999×999
=1000+999×(1+999)
=1000+999×1000
=1000×(999+1)
=1000×1000
=1000000

1000+999+999*999
1000+999*(1+999)
1000+999*1000
1000*(1+999)
1000*1000
1000000