1 a³-a²b-ab²+a²b+a²b+b³=a³-a²b+a²b-ab²+a²b+b³=a³+b³ 2 1\4x³-5x²+2x-4,其中x=2原式=1/4*8-5*4+2*2-4=2-20+4-4=-18