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: Bài 3: Phân tích các đa thức thành nhân tử: 1) x^2 – y2 + 5y – 5x 2) x^3 + 9x^2 – 4x – 36 3) 5x(

Toán Lớp 8: Bài 3: Phân tích các đa thức thành nhân tử:
1) x^2 – y2 + 5y – 5x 2) x^3 + 9x^2 – 4x – 36 3) 5x(x – 2y) + 6y(2y – x)
4) 3x(x – y) – 4y(x – y) 5) x2 – 2x – y^2 + 1 6) y^2 – 9x^2
7) x2 + x + 3(x + 1) 8) 3x^2 + 6xy + 3y^2 – 3z^2 9) 9z^2 – x^2 + 2xy – y^2
cần gấp trc 13h ạ

Comments ( 1 )

  1. Lời giải:
    1)
    x^(2)-y^(2)+5y-5x
    =(x^(2)-y^2)-5x+5y
    =(x-y)(x+y)-5(x-y)
    =(x-y)(x+y-5)
    2)
    x^(3)+9x^(2)-4x-36
    =x^(2)(x+9)-4(x+9)
    =(x+9)(x^(2)-4)
    =(x+9)(x-2)(x+2)
    3)
    5x(x-2y)+6y(2y-x)
    =5x(x-2y)-6y(x-2y)
    =(x-2y)(5x-6y)
    4)
    3x(x-y)-4y(x-y)
    =(x-y)(3x-4y)
    5)
    x^(2)-2x-y^(2)+1
    =x^(2)-2x+1-y^2
    =(x-1)^(2)-y^2
    =(x-1-y)(x-1+y)
    6)
    y^(2)-9x^2
    =y^(2)-(3x)^2
    =(y-3x)(y+3x)
    7)
    x^(2)+x+3(x+1)
    =x(x+1)+3(x+1)
    =(x+1)(x+3)
    8)
    3x^(2)+6xy+3y^(2)-3z^2
    =3.(x^(2)+2xy+y^(2)-z^2)
    =3.[(x+y)^(2)-z^2]
    =3.(x+y-z)(x+y+z)
    9)
    9z^(2)-x^(2)+2xy-y^2
    =(3z)^(2)-(x^(2)-2xy+y^2)
    =(3z)^(2)-(x-y)^2
    =(3z-x+y)(3z+x-y)

Leave a reply

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

About Nhi