若x+y=8,x²-y²=48,则y-x=
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
若实数X,Y满足X²+Y²+4X-2Y +1=0,则X²-6X+Y²-2Y的最大
若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值
若【2x²-3y²-10y+5】²+根号x-2y,则x= y=
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于
若x²-y²=40,x+y=8/5,则x-y=(),
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值