x+2的绝对值+(y-1/2)²=0
∴x+2=0
y-1/2=0
∴x=-2
y=1/2
3(x的平方y-x y的平方)-(5x的平方y-4x y的平方),
=3x²y-3xy²-5x²y+4xy²
=-2x²y+xy²
=xy(-2x+y)
=-1(4+1/2)
=-9/2
x+2的绝对值+(y-1/2)²=0
∴x+2=0
y-1/2=0
∴x=-2
y=1/2
3(x的平方y-x y的平方)-(5x的平方y-4x y的平方),
=3x²y-3xy²-5x²y+4xy²
=-2x²y+xy²
=xy(-2x+y)
=-1(4+1/2)
=-9/2