Question

(x+4)(x2 –4x+16)+(x–4)(x2 +4x+16)

Answer 1

$(x+4)( x^{2} -4x+16)+(x-4)( x^{2} +4x+16)$

$( x^{3}+64)+ ( x^{3} -64)$

$x^{3}+64 + x^{3} -64$

$2 x^{3}$