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: Làm tính nhân: a) (1/2x + y)(1/2x + y); b) (x -1/2y)(x – 1/2y)

Toán Lớp 8: Làm tính nhân:
a) (1/2x + y)(1/2x + y);
b) (x -1/2y)(x – 1/2y)

Comments ( 2 )

  1. a) (1/2x + y)(1/2x + y)
    = 1/2x . 1/2x +1/2 x . y + y . 1/2x + y . y
    = 1/4x2 +1/2 xy +1/2 xy + y2
    =1/4x2 + xy + y2
    b) (x – 1/2y)(x – 1/2y)
    = x . x + x(-1/2y) + (-1/2y . x) + (- 1/2y)(-1/2y)
    = x2 – 1/2xy – 1/2xy + 1/4y2
    = x2 – xy + 1/4y2
     

  2. $a. (1/2x+y)(1/2x+y)=(1/2x+y)^2=1/4x^2+4xy+y^2
    b, (x-1/2y)(x-1/2y)= x^2-2x+1/4y^2$

Leave a reply

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