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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 7: Tìm x : ( 1/1.101 + 1/2.102 + … + 1/10.110 ) x = 1/11 + 1/2.12 + … + 1/100.110

Toán Lớp 7: Tìm x :
( 1/1.101 + 1/2.102 + … + 1/10.110 ) x = 1/11 + 1/2.12 + … + 1/100.110

Comments ( 2 )

  1. Giải đáp+Lời giải và giải thích chi tiết:
    \(A=\frac{1}{1.101}+\frac{1}{2.102}+\frac{1}{3.103+…}+\frac{1}{10.110}\)
    \(A=\frac{1}{100}(\frac{100}{1.101}+\frac{100}{2.102}+\frac{100}{3.103}+…+\frac{100}{10.110})\)
    \(A=\frac{1}{100}(\frac{1}{1}-\frac{1}{101}+\frac{1}{2}-\frac{1}{102}+…+\frac{1}{10}-\frac{1}{110})\)
    \(A=\frac{1}{100}((\frac{1}{1}+\frac{1}{2}+…+\frac{1}{10})-(\frac{1}{101}+\frac{1}{102}+…+\frac{1}{110}))\)     
    \(B=\frac{1}{1.11}+\frac{1}{2.12}+…+\frac{1}{100.110}\)
    \(B=\frac{1}{10}(\frac{10}{1.11}+\frac{10}{2.12}+…+\frac{10}{100.110})\)
    \(B=\frac{1}{10}(\frac{1}{1}-\frac{1}{11}+\frac{1}{2}-\frac{1}{12}+…+\frac{1}{100}-\frac{1}{110})\)
    \(B=\frac{1}{10}((\frac{1}{1}+\frac{1}{2}+…+\frac{1}{100})-(\frac{1}{11}+\frac{1}{12}+…+\frac{1}{110}))\)=\(\frac{1}{10}((\frac{1}{1}+\frac{1}{2}+…+\frac{1}{10})-(\frac{1}{101}+\frac{1}{102}+…+\frac{1}{110}))\)
    X=10
    #Phamvanminh5599
    Xin câu trả lời hay nhất xin lỗi mình làm hơi lâu ~
     
     
     
     

  2. Giải đáp:
     x = 10
    Lời giải và giải thích chi tiết thích:
    (100/1.101 + 100/2.102 + 100/3.103 +….+100/10.110) . x
    = (10/1.11 + 10/2.12 + 10/100.110 )10
    =>(1+1/2+1/3+…+1/10-1/101-…-1/110)x
    =(1+1/2+1/3+…+1/10+1/11+…+1/100-1/11-…-1/100-1/101-…-1/110)10 =>(1+1/2+1/3+…+1/10-1/101-…-1/110)x
    =(1+1/2+1/3+…+1/10-1/101-…-1/110)10 

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222-9+11+12:2*14+14 = ? ( )

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