已知(4x-2y-1)²+根号(xy-2)=0,求4x³y-4x²y²+xy³的值
问题描述:
已知(4x-2y-1)²+根号(xy-2)=0,求4x³y-4x²y²+xy³的值
答
由(4x-2y-1)²+√(xy-2)=0可知 4x-2y-1=0 xy-2=0即 2x-y=1/2 xy=2所以 4x³y-4x²y²+xy³=xy(4x²-4xy+y²)=xy(2x-y)²=2×(1/2)²=1/2