Question

\(x^2-2xy+y^2-z^2\)

Answer 1

Ta có: x²-2xy+y²-z²

    = (x-y)²-z²

   = (x-y-z)(x-y+z)

Answer 2

\(x^2-2xy+y^2-z^2\\ =\left(x^2-2xy+y^2\right)-z^2\\ =\left(x-y\right)^2-z^2\\ =\left(x-y-z\right)\left(x-y+z\right)\)

Answer 3

\(x^2-2xy+y^2-z^2\)

\(=\left(x-y\right)^2-z^2\)

\(=\left(x-y-z\right)\left(x-y+z\right)\)