Question

Regroup and factorise the following :(x^2-2xy+y^2)-z^2

Answer 1

Answer:

$(x-y+z)(x-y-z)$

Step-by-step explanation:

Identity!

BASIC BUT IMPORTANT : $a^2-b^2=(a+b)(a-b)$.

$x^2-2xy+y^2=(x-y)^2$.

∴$(x-y)^2-z^2=(x-y+z)(x-y-z)$

Answer 2

Step-by-step explanation:

$< {x}^{2} - 2xy + {y }^{2} - {z}^{2} > \\ < {x - y} > ^{2} - {z}^{2} \\ < x - y + z >< x - y - z >$

by identities a^2-b^2

and (a-b) ^2