1.(-x/y)^2*(-y^2/x)^3/(-xy^4) 2.把x^5,x+1/x和1+2/x+3/x^2乘起来得到一个式子,它的最高次项的次数是?

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简y(x+y)+(x+y)(x-y)-x^2 (x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 因式分解x(x+y)(x-y)-x(x+y)^2 1.（x+2)^2-(x+y)^32.(x-y)^2-(x-y)^33.(x-y)^2-(y-x)^3 [(x-y)^2-(x+2y)(x-2y)]/y 计算:y-x分之x+y+x-y分之y-y-x分之2x-y 先化简 再求值(x-2y)(2y-x)+(2x+y)(2x-y )-(x-2y)(2x+y) 其中x=-2,y=-1. x^2-y分之y(x-y)-x(x+y)除以x+y分之x^2+y^2.其中x=2,y=-1.先化简再求值. x^2(x-y)+(y-x) x(x-y)2-(y-x)3 因式分解：a(x-y)^2+b(y-x)^3 4(x-y)^2+8(y-x)(x+y)1.a(x-y)^2+b(y-x)^3 2.4(x-y)^2+8(y-x)(x+y) 【(x-y)^2+(x+y)(x-y)】除以 2x [(x-y)²+(x+y)(x-y)]除以2x 1.（x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2) [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x 化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/(x+y)/x