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: Tìm x A) 57×63 B) x(x+1)(x mũ2 -4)=0

Toán Lớp 8: Tìm x
A) 57×63
B) x(x+1)(x mũ2 -4)=0

Comments ( 2 )

  1. Giải pháp
    a) ${57×63=3591 }$ 
    b) ${x(x+1)(x ^{ 2−4} )=0}$ 
    ${x(x+1)x^{ −2} =0}$
    ${x^{ −1} (x+1)=0}$
    ${x ^{ −1} x+x ^{ −1} =0}$
    $\dfrac{1}{x}x$ $+\dfrac{1}{x}=0$ ${1x+1=0}$ 
    ${1x=−1}$
    $x={-1}$
    Vậy $x=-1$
     

  2. A,
    57×63
    =(60-3)(60+3)
    =60^2-3^2
    =3600-9
    =3591
    B,
    x.(x+1).(x^2-4)=0
    x.(x+1).(x-2).(x+2)=0
    TH1
    x=0
    TH2
    x+1=0
    x=-1
    TH3
    x-2=0
    x=2
    TH4
    x+2=0
    x=-2

Leave a reply

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