x=2,y=1,1/xy+1/(x+1)(y+1)+1/(x+2)(y+2)+…+1/(x+2010)(y+2010)=
x+y=1,xy=-1/2,求x(x+y)(x-y)-x(x+y)2
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
先化简,再求值(x-y/x+y)^2÷(y-x/x^2+2xy+y^2)^2*1/x+y,其中x=-4,y=1
1/x-1/y=3,求2x+3xy-2y/x-y
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+2(xy+y)的值
已知X+Y=-1,xy=-2,求代数式-5(x+y)+(x-y)+(xy+y)的值
(1)正数x,y满足x^2-y^2=2xy,求(x-y)/(x+y)
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
x+y)(x-y)+(x-y)^2-(6x^2y-2xy^2)/2y,其中x=-2,y=1/3