Giải thích các bước giải:
$x^3-3x^2-4x-12$
$x^3-3x^2-4x+12-24$
$x^2(x-3)-4(x-3)-24$
$(x-3)(x+2)(x-2)-24$
B
$(x+y+z)3−x^3−y^3−z^3$
$3(xyz+x^2y+x^2z+xz^2+xy^2+y^2z+xyz+yz^2)$
$3[xy(x+z)+xz(x+z)+y2(x+z)+yz(x+z)]$
$3(x+z)[xy+xz+y^2+yz]$
$3(x+z)[x(y+z)+y(y+z)]$
$3(x+z)(y+z)(x+y)$