若(x+y)²=36,(x-y)²=16,则xy=_______,x²+y²=_
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x+y=1,xy=-30,则(x-y)²的平方根是_______.
已知有理数x,y满足xy=4,x+y=7,则x²y+xy²=()?
若x+y=10,xy=24,则x²+y²=?(x-y)²=?
2x²-3xy=y²=0(x,y不得o)求x/y+y/x
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
若x+y=10 xy=-1 则x²+y²=(x+y)²-2xy=
已知2x+y=0,求x-2y/x²+xy*(x²-y²)/x²-4xy+4y
已知X²+3XY-4Y²=0(Y≠0)求X-Y/X+Y
已知y=(x²-3xy-2y²)/2y,则x:y的值为
若x-y=1,xy=5,则x²y-xy²=?
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²