速算和巧算的奥数题:2003x20022001-2001x20022003..2004-2001+1998-1995+1
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速算和巧算的奥数题:2003x20022001-2001x20022003..2004-2001+1998-1995+1992-1989..+12-9+6-3要过
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急救急救急救急救
![速算和巧算的奥数题:2003x20022001-2001x20022003..2004-2001+1998-1995+1](/uploads/image/z/4850989-61-9.jpg?t=%E9%80%9F%E7%AE%97%E5%92%8C%E5%B7%A7%E7%AE%97%E7%9A%84%E5%A5%A5%E6%95%B0%E9%A2%98%3A2003x20022001-2001x20022003..2004-2001%2B1998-1995%2B1)
1)
2003*20022001-2001*20022003
=(2002+1)*20022001-[(2002-1)*(20022001+2)]
=2002*20022001+20022001-(2002*20022001+4004-20022001-2)
=20022001+20022001-4004+2
=40040000
2)
原式=(2004-2001)+(1998-1995)+.+(6-3)
=3+3+…… (3*2004/2/3)
=2004/2=1002
2003*20022001-2001*20022003
=(2002+1)*20022001-[(2002-1)*(20022001+2)]
=2002*20022001+20022001-(2002*20022001+4004-20022001-2)
=20022001+20022001-4004+2
=40040000
2)
原式=(2004-2001)+(1998-1995)+.+(6-3)
=3+3+…… (3*2004/2/3)
=2004/2=1002