Respuesta :

9514 1404 393

Answer:

  (x -y -1)(x +y)

Step-by-step explanation:

The expression can be factored by grouping.

  x^2 -y^2 -x -y = (x^2 -y^2) -(x +y)

  = (x -y)(x +y) -1(x +y)

  = (x -y -1)(x +y)

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It is useful to know that a difference of squares is factored as ...

  a^2 -b^2 = (a -b)(a +b)