4x^2y-[2xy^2-2(xy-2分之1x^2y)]+3xy^2
=4x^2y-2xy^2+2(xy-2分之1x^2y)+3xy^2
=4x^2y+xy^2+2xy-x^2y
=3x^2y+xy^2+2xy
=-27/16+3/4-3/2
=-39/16
4x^2y-[2xy^2-2(xy-2分之1x^2y)]+3xy^2
=4x^2y-2xy^2+2(xy-2分之1x^2y)+3xy^2
=4x^2y+xy^2+2xy-x^2y
=3x^2y+xy^2+2xy
=-27/16+3/4-3/2
=-39/16