求19+199+1999+19999·······+1999···99(2002个9)的简便计算
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![求19+199+1999+19999·······+1999···99(2002个9)的简便计算](/uploads/image/z/134768-56-8.jpg?t=%E6%B1%8219%2B199%2B1999%2B19999%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%2B1999%C2%B7%C2%B7%C2%B799%EF%BC%882002%E4%B8%AA9%EF%BC%89%E7%9A%84%E7%AE%80%E4%BE%BF%E8%AE%A1%E7%AE%97)
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求19+199+1999+19999·······+1999···99(2002个9)的简便计算
求19+199+1999+19999·······+1999···99(2002个9)的简便计算
求19+199+1999+19999·······+1999···99(2002个9)的简便计算
19+199+1999+19999·······+1999···99(2002个9)
=20-1+200-1+2000-1+.+20000..0(2002个0)-1
=2222222.22(2003个2)-2002
=2222.222220220 (共2003位)
各项都先加1 得2222。。。20 2002个2 再减2002
19+199+1999+19999·······+1999···99(2002个9)
=20-1+200-1+2000-1+20000-1+.......+200000(2002个0)-1
=2222222222.....20(2002个2)-2002
=222222......22220-2002
=222222.....20218(前边有1999个2)