(2x+y)（2x-3y)+x（2x+y)
=(2x+y)(2x-3y+x)
=(2x+y)(3x-3y)
=3(2x+y)(x-y)
8^2(2x^2-y^2）+y^4
=64(2x^2-2y^2)+y^4+64y^2
=128(x^2-y^2)+y^2(y^2+64)
=128(x+y)(x-y)+y^2(y^2+64)
3x^2-27
=3(x^2-9)
=3(x+3)(x-3)