由|x-2|+x²-xy+y²/4=0
|x-2|+(x-y/2)²=0
∴x-2=0, x=2
x-y/2=0, y=4
x²(x²-xy+y)-x(x³-2x²y+xy-1)
=4(4-8+4)-2(8-32+8-1)
=4×0-2×(-17)
=-34.
由|x-2|+x²-xy+y²/4=0
|x-2|+(x-y/2)²=0
∴x-2=0, x=2
x-y/2=0, y=4
x²(x²-xy+y)-x(x³-2x²y+xy-1)
=4(4-8+4)-2(8-32+8-1)
=4×0-2×(-17)
=-34.