Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

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

Toán Lớp 6: Cho A=1+2^1+2^2+-+2^100+2^101

Toán Lớp 6: Cho A=1+2^1+2^2+….+2^100+2^101

Comments ( 2 )

  1. Lời giải và giải thích chi tiết:
    -Ta có: A =1+2^1+2^2+……+2^100+2^101
    => A=(1+2+2^2)+…..+(2^99+2^100+2^101)
    => A=(1+2+4)+…….+2^99 . (1+2+4)
    => A=7 . (1+……….+2^99) vdots 7
    => A vdots 7 (đpcm)

  2. $A = 1 + 2 + 2^{2} + … + 2^{100} + 2^{101}$
    $A = (1 + 2 + 2^{2}) + (2^{3} + 2^{4} + 2^{5}) + … + (2^{99} + 2^{100} + 2^{101})$
    $A = 7 + 2^{3} . (1 + 2 + 2^{2}) + … + 2^{99} . (1 + 2 + 2^{2})$
    $A = 7 + 2^{3} . 7 + … + 2^{99} . 7$
    $A = 7 . (1 + 2^{3} + … + 2^{99})$
    → $\text{A chia hết cho 7.}$

Leave a reply

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

About Lan Anh