(1)原式=35x³-79x²+70x-24
(2)原式=(2x)³-(1)³=8x³-1.利用立方差公式x³-y³=(x-y)(x²+xy+y²)
(3)原式=(a-c)²-b²=a²-b²+c²-2ac.利用平方差公式x²-y²=(x-y)(x+y)
(4)原式=(2x-3y)²-z²=4x²+9y²-z²-12xy.利用平方差公式x²-y²=(x-y)(x+y)
(5)原式=(x²-9)(x²+9)=x^4-81
(6)原式=(x-y+x+y)[(x-y)²-(x-y)(x+y)+(x+y)²]
=2x[x²+3y²]
=2x³+6xy².利用立方和公式x³+y³=(x+y)(x²-xy+y²)