[tex]1.\\\\ (4x-3y)(16x^2+12xy-9y^2)=\\\\=4x\cdot 16x^2+4x\cdot 12xy-4x\cdot 9y^2 -3y\cdot 16x^2-3y\cdot12xy+ 3y\cdot9y^2=\\\\=64x^3+ 48x^2y- 36xy^2 - 48x^2y- 36xy^2+ 27y^3=\\\\=64x^3-72xy^2 + 27y^3[/tex]
[tex]2.\\\\ (4x-3y)(16x ^2-12xy+9y^2)=\\\\=4x\cdot 16x^2-4x\cdot 12xy+4x\cdot 9y^2 -3y\cdot 16x^2+3y\cdot12xy- 3y\cdot9y^2=\\\\=64x^3- 48x^2y+ 36xy^2 - 48x^2y+ 36xy^2-27y^3=\\\\=64x^3-96x^2y +72xy^2 - 27y^3[/tex]