Question

factorise x²+y²-z²-2xy

Answer 1

Factorisation of $x^2+y^2-z^2-2xy$ is (x-y+z)(x-y-z).

Step-by-step explanation:

We have to factorise,

$x^2+y^2-z^2-2xy$

= x$^2+y^2-2xy-z^2\ [(a-b)^2 =a^2+b^2-2ab]$

= $(x-y)^2-z^2\ [(a-b)(a+b)=a^2-b^2]$

= (x-y+z)(x-y-z)    

Hence,factorisation of $x^2+y^2-z^2-2xy$ is (x-y+z)(x-y-z).

Answer 2

Answer:

x^2+y^2-z^2-2xy [(a-b)^2=a^2+b^2-2ab]

=(x-y)^2-z^2

=(x-y+z)(x-y-z