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 7: Cho yz:zx =1:2 . Hãy tính x/yz : y/zx

Toán Lớp 7: Cho yz:zx =1:2 . Hãy tính x/yz : y/zx

Comments ( 2 )

  1. Theo đề bài ta có :
    yz=zx=1:2
    =>\frac{yz}{zx}=1/2
    =>y/x=1/2
    =>x/y=2/1=2
    Lại có :
    \frac{x}{yz}:\frac{y}{zx}
    =\frac{x}{yz}.\frac{zx}{y}
    =\frac{x^2}{y^2}
    Do đó : \frac{x}{yz} : \frac{y}{zx}=\frac{x^2}{y^2}=4:1=4

  2. Vì yz : zx = 1 : 2 nên (yz)/(xz) = 1/2
         => y/x = 1/2
         => x/y = 2/1 = 2
    Ta có: x/(yz) : y/(zx)
       = x/(yz) xx (zx)/y = (x^2z)/(y^2z)
       = (x^2)/(y^2) = (x/y)^2
       = 2^2 = 4
    Vậy, x/(yz) : y/(zx) = 4
       

Leave a reply

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