(x-y)（x+xy+y）+xy（y-x）和3（x-1)-18(x-1)+27分解因式要过程拜托各位了 3Q

|x|/x+y/|y|+xy/|xy|= -x-3xy+y xy-1+x-y 集合{(x,y)|xy （x-y+4xy/x-y）(x+y-4xy/x-y) xy(x-y)-x(x-y)² 【x(xy-xy)-y(x-xy)】÷3xy 计算：(xy-x²)×x-y/xy 【xy-x²】*xy/x-y (xy-x²)÷(x²-2xy+y²/xy)×（x-y/x²） x-y/x²÷x²-2xy+y²/xy*（xy-x²） x根号x+x根号y/xy-y^2)-（x+根号xy+y/x根号x-y根号）y （x^2+xy/x-y)/（xy/x-y)计算 计算：[x(x²y²-xy)-y(x²-x³y）]/3xy 化简x^-y^/x^-2xy+y^ (-x-y)(x^2+xy+y^2) 2*(x-y)²(y-x)(xy) （√xy -xy分之x+√xy）除以√xy -y分之x-y（x>0,y.0）