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