2999+999X999的巧妙运算

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2999+999X999的巧妙运算
2999+999X999的巧妙运算

2999+999X999的巧妙运算
2999+999×999
=2000+999+999×999
=2000+999×(1+999)
=2000+999000
=1001000

2999+999×999
=3×1000-1+(1000-1)×(1000-1)
=3×1000-1+1000000-2×1000+1
=1000000+1×1000
=1000000+1000
=1001000

2999+999X999
=2999+999*(1000-1)
=2999+999000-999
=2000+999000
=1001000

2999+999X999
=2000+999 +999X999
=2000+999*(999+1)
=2000+999000
=(2+999)*1000
=1001000