Question

solve this question please

Answer 1

$(x + y + z) {}^{2} - (x + y + z) {}^{2}$

Here Apply
$a {}^{2} - b {}^{2} = (a + b)(a - b)$

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

$(2x + 2y + 2z)(0)$


$0$



$thanks$