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: (3-x) (x²+2xy-1) help meeeeeeeee

Toán Lớp 8: (3-x) (x²+2xy-1) help meeeeeeeee

Comments ( 1 )

  1. Cách 1 :
       ( 3 – x )( x^2 + 2xy – 1 )
    = 3.x^2 + 3 . 2xy – 3 . 1 – x . x^2 – x . 2xy + x . 1
    = 3x^2 + 6xy – 3 – x^3 – 2x^2y + x
    = x^3 – 3x^2 – 2x^2y + 6xy + x – 3
    Cách 2 :
       ( 3 – x )( x^2 + 2xy – 1 )
    = ( 3 – x ) . [-( x^2 – 2xy + 1^2 ]
    = ( 3 – x ) . [ -( x – 1 )^2]
     

Leave a reply

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