化简求值：x³-x²y+xy²-y²x+y³;其中x=3/2,y=-4/3.
原式=x³-x²y+y³=x²(x-y)+y³=(9/4)(3/2+4/3)-(64/27)
=(9/4)(15/6)-(64/27)=(45/8)-(64/27)=703/216