1、解:(1)原式=x³ +2x²+1/2x
=2x²-4x-1
=x³-7/2x-1.
(2)原式=a³ -a² b+ab²-aX b+ab²-b³
=a³ -2a²b+2ab²-b³.
(3)原式=(6x² -15x- 4x+10) (x+1)
= (6x² -19x+10) (x+1)
=6x³ -19x²+10x+ 6x²-19x+ 10
=6x³-13x² -9x+10.
(4)原式=(x+y)(x²-2xy+y²)
=x³-2x² y+xy²+ x²y- 2xy²+ y³
=x³ -x² y-xy² +y³.