当x=2012,y=-2011时,求代数式(x^4-y^4)/(x²-2xy+y²)·(y-x)/(
当x=2012,y=-2011时,求代数式(x^4-y^4)/(x²-2xy+y²)·(y-x)/(
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
当x=-4 y=-2时 求代数式-3x平方y+3xy平方+x?+3x平方y-3xy平方-y,
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)的值
当x=2008,y=2009时,求代数式(x-y)/x/(x-(2xy-y^2)/x)
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*
当x=根号6,y=根号2时,求代数式xy分之x²-y²-xy-x²分之xy-y²
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
x(x-2)-(x²-2y)=-4求代数式1/2(x²+y²)-xy的值...
当x=2,y=1时,代数式x^4-xy^3-x^3y-3x^2y+3xy^2+y^4
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy