Question

x^2-2xy+y^2-z^2 please help me to factorise as soon as possible​

Answer 1

${x}^{2} - 2xy + {y}^{2} - {z}^{2} \\ = {x}^{2} - {z}^{2} + {y}^{2} - 2xy \\ = (x + z)(x - z) + y(y - 2x)$

${x}^{2} - 2xy + {y}^{2} - {z}^{2} \\ = {x}^{2} + {y}^{2} - 2xy - {z}^{2} \\ = {(x + y)}^{2} - 2xy - 2xy - {z}^{2} \\ = (x + y)(x + y) - 4xy - {z}^{2}$