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 phép chia bằng cách áp dụng hằng đẳng thức: a) (x^8 – 2x^4y^4+y^8):(x^2+y^2)

Toán Lớp 8: Làm phép chia bằng cách áp dụng hằng đẳng thức:
a) (x^8 – 2x^4y^4+y^8):(x^2+y^2)

Comments ( 1 )

  1. Ta có: $x^8-2x^4y^4+y^8$
    $= (x^4)^2-2.x^4 .y^4+(y^4)^2$
    $= (x^4-y^4)^2$
    $= (x^4-y^4)(x^4-y^4)$
    $= (x^2-y^2)(x^2+y^2)(x^2-y^2)(x^2+y^2)$
    $= (x^2-y^2)^2(x^2+y^2)^2$
    $\to (x^8-2x^4y^4+y^8):(x^2+y^2)$
    $\leftrightarrow (x^2-y^2)^2(x^2+y^2)^2 :(x^2+y^2)$
    $\leftrightarrow \dfrac{(x^2-y^2)^2(x^2+y^2)^2}{x^2+y^2}$
    $\leftrightarrow (x^2-y^2)^2(x^2+y^2)$
    $\leftrightarrow (x^4-2x^2y^2-y^4)(x^2+y^2)$
    $\leftrightarrow x^8-2x^4y^2-x^2y^4+x^4y^2-2x^2y^4-x^2y^4-y^8$
    $\leftrightarrow x^8-x^4y^2-4x^2y^4-y^8$

Leave a reply

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