1/2xy+(x-2y)(x+2y)-1/2(2x-3y)(x+2y)

.(x+y-2)(x+y-2xy)+(xy-1)^2 (x+y)(x+y+2xy)+(xy+1)(xy-1)(x+y)(x-y)+4(y-1) 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) {(x-y/x^2-2xy+y^2)-(xy+y^2/x^2-y^2)}*(xy/y-1) (x/x+y-x/y-x-2xy/x.x-y.y)/(1/x-1/y) 分式化简 因式分解x^2y^2+x^2y+xy^2+3xy+x+y+1 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 计算3xy[2xy-x(y-2)+x-1] xy-x-y+1/y²-2y+1 y平方-2y+1分之xy-x-y-1 x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² [(x+y)^2-(x-y)^2]÷(1/2xy) 1.（xy-1）^2-(x+y-2xy)(2-x-y)2.(x+y)(x+y+2xy)+(xy-1)(xy+1) (x/y)^2乘以(xy)^-2除以(x^-1y) 因式分解 x(x-1)+y(y+1)-2xy 因式分解:X(X-1)+Y(Y+1)-2XY x-y/x^2+xy除以xy-x^2/x^2y^2-x^4*1/x-y （x+y）(x-1)-xy-y^2 怎么因式分解?