-5y²+{2xy-[y²+x²-(1-y²)+2xy]+3x²｝
=-5y²+{2xy-y²-x²+(1-y²)-2xy+3x²｝
=-5y²-2y²+2x²+1
=-7y²+2x²+1
=-7*(-2)²+2*(3/2)²+1
=-28+9/2+1
=-45/2