Question

Pls answer correctly I will mark as brainliest

Answer 1

Answer:

$0$

Step-by-step explanation:

$(x + y)(x - y) + (y + z)(y - z) + (z + x)(z - x) = {x}^{2} - {y}^{2} + {y}^{2} - {z}^{2} + {z}^{2} - {x}^{2} \\ \\ = 0 \: \: \: .$