3x²y-[2xy²-2（xy-3/2 x²y）]+3xy²
=3x²y-（2xy²-2xy+3x²y）+3xy²
=3x²y-2xy²+2xy-3x²y+3xy²
=-2xy²+2xy+3xy²
=xy²+2xy
=xy(y+2) x=3,y=-1/3
=-1(-1/3+2)
=-5/3