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

Toán Lớp 6: B = 1 + 3 + 5 + … + 97 + 99 help me!!!!!!

Toán Lớp 6: B = 1 + 3 + 5 + … + 97 + 99 help me!!!!!!

Comments ( 2 )

  1. 1+3+5+7+…+97+99
    Số số hạng là:
    (99-1):2+1
    =98:2+1
    =49+1=50
    Tổng là:
    (99+1) x 50:2
    =100 x 50:2
    =5000:2=2500

  2. $\text{B = 1 + 3 + 5 +…+ 97 + 99}$
    $\text{= ( 1 + 99 ), ( 3 + 97 ) +…+(49 + 54) }$
    $\text{= 100 + 100 +…+ 100}$
    $\text{⇒ Ta có: ( 99 – 1 ) : 2 + 1 = 50 số}$
    $\text{100 . 50 = 5000}$
    $\text{Vậy B = 5000}$
     #BanhQuyy

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