Question

How to solve {x+y+z} {x-y-z} ?

Answer 1

{x+y+z}{x-(y+z)}.
reason because
(a-b)(a+b)=a^2-b^2

so. {x^2-(y+z)^2}
=x^2-y^2-z^2-2yz

Answer 2

x^2-(y+z)^2} =x^2-y^2-z^2-2yz is the answer