Question

reduce e= (x+3) (x2-3x+9) + (x2+3x+9) (x-3)

Answer 1

$(x+3) (x^{2}-3x+9)+(x-3) (x^{2}+3x+9)$
$x^{3}- 3x^{2}+9x+3 x^{2} -9x+27+x^{3}+ 3x^{2}+9x-3 x^{2} -9x-27$
$2 x^{3}$