Answer :

[tex] 9x^2y-24xy^2-16y^3=y(9x^2-24xy-16y^2)\\\\=y(9x^2-24xy+16y^2-32y^2)=y[(3x)^2-2\cdot3x\cdot4y+(4y)^2-32y^2]\\\\=y[(3x-4y)^2-32y^2]=y[(3x-4y)^2-16\cdot2y)]\\\\=y[(3x-4y)^2-(4\sqrt2\ y)^2]=y(3x-4y-4\sqrt2\ y)(3x-4y+4\sqrt2\ y) [/tex]
9x2y - 24xy2 + 16y3

= y( 9x2 - 24xy + 16y2)

= y{ (3x)2 - 2(3x)(4y) + (4y)2 }

= y{ (3x - 4y)2 }

= y (3x -  4y) (3x -  4y)