已知（4x-y-1）²+根号下x+y-2=0 求4x²y-4xy-xy²

已知（4x-y-1）²+根号下x+y-2=0 求4x²y-4xy-xy²
已知（4x-y-1）²+根号下x+y-2=0 求4x²y-4xy-xy²

已知（4x-y-1）²+根号下x+y-2=0 求4x²y-4xy-xy²
（4x-y-1）²+根号下x+y-2=0
4x-y-1=0
x+y-2=0
x=3/5,y=7/5
4x^2y-4xy-xy^2
=xy(4x-4-y)
=3/5*7/5*(12/5-4-7/5)
=21/25*(-3)
=-63/25