X^2-2XY+Y^2-X+Y-2=0怎么算等于(x-y-2)(x-y+1)?

2xy/(x+y)(x+y)与x/(x+y)(x-y)怎么通分 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? (x^2-xy)y÷y-x/xy怎么做? 整数x,y满足方程2xy+x+y=83,则x+y怎么算 设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于 因式分解：x×x-xy-2y×y-x-y 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) y分之x等于2分之1 xy怎么算 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* x+y=1,xy=-1/2,求x(x+y)(x-y)-x(x+y)2 （x+2y-3y)- (-2x-y+xy ) 其中x+y=0.5 xy等于-0.5 已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}