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 9: căn (2x+5)=0 căn x=x giúp e vs ạ

Toán Lớp 9: căn (2x+5)=0 căn x=x giúp e vs ạ

Comments ( 2 )

  1. ***Lời giải***
    \sqrt{2x+5}=5
    ĐK: x≥-5/2
    <=>2x+5=25
    <=>2x=25-5
    <=>2x=20
    <=>x=10(N)
    Vậy S={10}
    \sqrt{x}=x
    ĐK: x≥0
    <=>x=x^2
    <=>x-x^2=0
    <=>x(1-x)=0
    <=>\(\left[ \begin{array}{l}x=0\\1-x=0\end{array} \right.\) 
    <=>\(\left[ \begin{array}{l}x=0(N)\\x=1(N)\end{array} \right.\) 
    Vậy S={0;1}
     

  2. sqrt{2x+5}=5(đk:x>=-5/2)
    <=> (\sqrt{2x+5})^2=5^2
    <=>2x+5=25
    <=>2x=20
    <=>x=10(t//m)
    Vậy S={10}
    __
    \sqrt{x}=x(đk:x>=0)
    <=>(\sqrt{x})^2=x^2
    <=>x=x^2
    <=>x-x^2=0
    <=>x(1-x)=0
    <=> \(\left[ \begin{array}{l}x=0\\1-x=0\end{array} \right.\) 
    <=> \(\left[ \begin{array}{l}x=0(t/m)\\x=1(t/m)\end{array} \right.\) 
    Vậy S={0;1}

Leave a reply

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