Question

(2x+ 3y+z)×(2x+3y+z)-(2x-3y +z)×(2x-3y+z)​

Answer 1

$(2x + 3y + z) {}^{2} - (2x - 3y + z) {}^{2} \\ 4x {}^{2} + 9y {}^{2} + z {}^{2} - (4x {}^{2} - 9y {}^{2} + z {}^{2} ) \\ 4x {}^{2} + 9y {}^{2} + z {}^{2} - 4x {}^{2} + 9y {}^{2} - z {}^{2} \\ = 18y {}^{2}$

Answer 2

$12y \times (2x + z)$