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: E=(5x-2y)*(25x^2+10xy+4y^2)-(125x^3-7y^3) x=25 y=-10

Toán Lớp 8: E=(5x-2y)*(25x^2+10xy+4y^2)-(125x^3-7y^3) x=25 y=-10

Comments ( 2 )

  1. E=(5x-2y)(25x^2+10xy+4y^2)-(125x^3-7y^3)
    E=(5x)^3-(2y)^3-125x^3+7y^3
    E=125x^3-8y^3-125x^3+7y^3
    E=-y^3
    Thay y=-10 vào E ta có:
    E=-(-10)^3=-(-1000)=1000
    Vậy E=1000 khi x=25;y=-10

  2. E = (5x – 2y)(25x^2 + 10xy + 4y^2) – (125x^3 – 7y^3)
      = (5x)^3 – (2y)^3 – 125x^3 + 7y^3
      = 125x^3 – 8y^3 – 125x^3 + 7y^3
      = -y^3
      = -(-10)^3
      = -(-1000)
      = 1000

Leave a reply

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