5x^y-[2x^2y-3(xy^2-2x^2y+2xy^2)]
=5x^y-[2x^2y-3xy^2+6x^2y-6xy^2]
=5x^y-2x^2y+3xy^2-6x^2y+6xy^2
=5x^y-8x^2y+9xy^2
|x-1|+(y+2)^2=0
所以 x-1=0 y+2=0
x=1 y=-2
代入上式得 5*1^-2-8*(-2)+9*(-2)^2
=5+16+36
=21+36
=57