Question

[Nguyễn Thị Như Quỳnh]

Phan tich da thuc thanh nhan tu:

1) P=125x^3 -8y^3

2) P= 4x(x-2y+8y(2y-x)

3) (2x+1)^2 - (x-1)^2

Cac ban ghi loi giai ro rang cho minh nha

Answer 1

[Nguyễn Thị Mỹ Hằng]

P= 125x^3-8y^3

  =5^3x^3-2^3y^3

  =(5x)^3-(2y)^3

  =(5x-2y)(25x^2+10xy+4y^2)

P=4x(x-2y)+8y(2y-x)

  =4x(x-2y)-8y(x-2y)

  =(4x-8y)(x-2y)

  =4(x-2y)(x-2y)

  =4(x-2y)^2

(2x+1)^2-(x-1)^2=(2x+1-x+1)(2x+1+x-1)

                       =(x+2)3x

K NHA!