x+y=-3 xy+x+y=-2 x/y+y/x=?

|x|/x+y/|y|+xy/|xy|= x+y=-3 xy+x+y=-2 x/y+y/x=? (-x+2y)(2x+y)-(2x+y)(y-2x)-3xy=?因式分解 x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? (x^3-2x^2+xy^2)/(x-y)+(x+y)(y-x)=? f(xy,x-y)=x^2+3xy+y^2,则f(x,y)=? 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 若1/x-1/y=2,求3x-2xy-3y/x-xy-y的值3x-2xy-3y/x-xy-y 不好意思，是3x-2xy-3y/x-2xy-y x-y/xy=( )/x^3y^2 x^2-4xy+3y^2=（x-3y)(x-y)x^2-4xy+3y^2 怎么分解成（x-3y)(x-y) x-y/x+y=-1/2,x*x-xy-2y*y/x*x-3xy+2y*y的解是多少?同上,请将过程写出, f(xy,x-y)=x^2+y^2+xy;f(x,y)/∂x;f(x,y)/∂y （-3x^y+2xy)-( )=4x^+xy 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 当x=2 y=2分之1 时,代数式(x+y)(x-y)+(x-y)^-(x^-3xy ) 已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y) X×X-2XY-Y×Y+2X-2Y+2=02X×2X-4XY-2Y×2Y+3X-3Y+4=0X×X+2XY+Y×Y+X+Y-56=0X×X-2XY+Y×Y-X+Y-12=0X×X-3XY+Y×Y=-13X×3X-XY+3Y×3Y=13 两个在一起的方程之间有所联系（要求一步一步写出来） f(x+y,x-y)=(x^2-y^2)/2xy,求f(x,y)!