Question

Prove that (x+y)(x-y)+(y+z)(y-z)+(z+x)(z-x)=0

Answer 1

Explanation:

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

=x²-y²+y²-z²+z²-x²

=0

Answer 2

x=0 x=y=z. with these presumed variable amounts, one can conclude that the equation you asked is equivalent to 0