先化简,在求值.3X^2+(-3/2X+1/3Y^2)(2X-2/3Y),其中X=-1/3,Y=2/3_数学解答

先化简,在求值.3X^2+(-3/2X+1/3Y^2)(2X-2/3Y),其中X=-1/3,Y=2/3

人气：305 ℃　时间：2019-08-21 15:10:00

解答

3X^2+(-3/2X+1/3Y^2)(2X-2/3Y),
=3X^2-3X^2+xy+2/3xY^2-2/9Y^3
=xy+2/3xY^2-2/9Y^3
=-1/3*2/3-2/3*1/3*4/9-2/9*8/27
=-94/243