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: Pttnt: a,21xy^2+14x^2y-7xy b,5x^2+10xy-45+5y^2

Toán Lớp 8: Pttnt:
a,21xy^2+14x^2y-7xy
b,5x^2+10xy-45+5y^2

Comments ( 2 )

  1. a,21xy^2+14x^2y-7xy
    =7xy(y+x-1)
    b,5x^2+10xy-45+5y^2
    =5(x^2+2xy-9+y^2)
    =5[(x^2+2xy+y^2)-3^2]
    =5[(x+y)^2-3^2]
    =5(x+y-3).(x+y+3)

  2. Giải đáp + Lời giải và giải thích chi tiết:
     a)
    21xy²+14x²y-7xy
    = 7xy.3y+7xy.2x-7xy.1
    = 7xy.(3y+2x-1)
    b)
    5x²+10xy-45+5y²
    = 5.(x²+2xy-9+y²)
    = 5.[(x²+2xy+y²)-9]
    = 5.[(x+y)²-3²]
    = 5.(x+y-3)(x+y+3)

Leave a reply

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