(3x+2y)(3x-2y)-(x-3y)(3x+y)
=9x²-4y²-3x²+8xy+3y²
=6x²+8xy-y²
2(2x-1)(2x+1)-5x(-x+3y)+4x(-4x^2-5/2y)
=2(4x²-1)+5x²-15xy-16x³-10xy
=-16x³+13x²-25xy-2
(3x+2y)(3x-2y)-(x-3y)(3x+y)
=9x²-4y²-3x²+8xy+3y²
=6x²+8xy-y²
2(2x-1)(2x+1)-5x(-x+3y)+4x(-4x^2-5/2y)
=2(4x²-1)+5x²-15xy-16x³-10xy
=-16x³+13x²-25xy-2