∵(x+2)²+|y+1|=0
∴x+2=0,y+1=0
x=-2,y=-1
∴5xy²-[2x²y-(2x²y-xy²)]
=5xy²-(2x²y-2x²y+xy²)
=5xy²-xy²
=4xy²
=4×(-2)×(-1)²
=-8