【4y^2—x^2/x^2+2xy+y^2】/【x—2y/2x^2+2xy】

（xy-x^2)乘以(xy)/(x-y) （x^2+xy/x-y)/（xy/x-y)计算 因式分解：x×x-xy-2y×y-x-y x^2y+4xy+4y (x^-4y^)/(x^+2xy+y^)/(x+2y)/(2x^+2xy) (x+y-2xy)(x+y-2)+(1-xy)² (x^2-xy)y÷y-x/xy怎么做? 作乘法:(x+y)(x^2-xy+y^2)；(x-y)(x^2+xy+y^2) (x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y) 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 （-3x^y+2xy)-( )=4x^+xy