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: Tính M M= 1+ 2+ 2^2+ 2^3+ …+ 2^15 / 2^17 – 2

Toán Lớp 6: Tính M
M= 1+ 2+ 2^2+ 2^3+ …+ 2^15 / 2^17 – 2

Comments ( 2 )

  1. Giải đáp:
     
    Lời giải và giải thích chi tiết:
    M = (1 + 2 + 2^2 +……..+ 2^15)/(2^17 – 2)
    -Đặt N = 1 + 2 + 2^2 +……..+ 2^15
            2N = 2 + 2^2 + 2^3 +……….+ 2^16
            2N – N = ( 2 + 2^2 + 2^3 +……….+ 2^16 ) – ( 1 + 2 + 2^2 +……..+ 2^15 )
            N = 2^16 – 1
    → M = (2^16 – 1)/(2^17 – 2)
    → M = (2^16 – 1)/(2 . (2^16 – 1))
    → M = 1/2

  2. M=(1+2+2^2+..+2^(15))/(2^(17)-2)
    ⇔2M=(2+2^2+..+2^(16))/(2^(17)-2)
    ⇔2M-M=(2+2^2+..+2^(16))/(2^(17)-2)-(1+2+2^2+..+2^(15))/(2^(17)-2)
    ⇔M=(2^(16)-1)/(2(2^(16)-1))
    ⇔M=1/2
     

Leave a reply

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

About Cát Linh