Question

(X + y + z)(x - y + z) + (x + y - z)(-x + y + z) -4zx

Answer 1

Answer:0

Step-by-step explanation:

(x+y+z)(x-y+z)+(x+y-z)(-x+y+z)-4zx

={(x+z)+y} {(x+z)-y} -{(x-z)+y} {(x-z)-y} -4zx

={(x+z)^2-y^2} -{(x-z)^2-y^2} -4zx

={x^2+2zx+z^2-y^2} - {x^2-2zx+z^2-y^2} -4zx

=x^2+2zx+z^2-y^2-x^2+2zx-z^2+y^2-4zx

=0