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 8: cho x^2/(x+y) + y^2/(y+z) + z^2/(z+x) = 2017. tinhs y^2/(x+y) + z^2/(y+z) + x^2/(z+x) -3

Tháng Mười Hai 6, 2022 Toán học 1 Comment 0 views

Toán Lớp 8: cho x^2/(x+y) + y^2/(y+z) + z^2/(z+x) = 2017. tinhs y^2/(x+y) + z^2/(y+z) + x^2/(z+x) -3

Comments ( 1 )

  1. thanhtung
    thanhtung
    6 Tháng Mười Hai, 2022 at 12:55 sáng
    Reply
    #LC
    Có x^2/(x+y)+y^2/(y+z)+z^2/(z+x)=2017
    Xét
    (x^2/(x+y) + y^2/(y+z) + z^2/(z+x))-(y^2/(x+y) + z^2/(y+z) + x^2/(z+x))
    = (x^2-y^2)/(x+y)+(y^2-z^2)/(y+z)+(z^2-x^2)/(x+z)
    = ((x-y)(x+y))/(x+y) +((y-z)(y+z))/(y+z)+((z-x)(x+z))/(x+z)
    =x-y+y-z+z-x
    =0
    => y^2/(x+y) + z^2/(y+z) + x^2/(z+x) =x^2/(x+y) + y^2/(y+z) + z^2/(z+x)  =2017
    => y^2/(x+y) + z^2/(y+z) + x^2/(z+x) – 3=2017-3=2014

Leave a reply

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

Tuyết lan

About Tuyết lan