计算 [ ( x+y ) ( x-y ) ] ^ 9 ÷ ( y-x )^ 8 ÷ ( -x-y )^9

已知x平方-6x+9与/y-1/互为相反数,计算(x/y-y/x)÷( x+y) 计算：(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^2 计算 [12(x+y)³(y-x)]³÷[4(x+y)²（x-y)]² [(2x+y)(x-3y)+y(x+3y)]÷(2x)计算, 计算:(x-y)(1/9x-y)-(1/3x-y)(1/3x+y) 计算：(x+y/x-y)÷(xy+x^2) 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) 计算：1.（x-1)^2+2(1-x) 2.(x-y)/(x+3y)÷(x^2-y^2)/(x^2+6xy+9y^2)- 计算 {2(x-y)的平方-8(x-y)的平方(x+y)+6y(x-y)的平方}÷2(x-y)的平方 等于 [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y {(x,y) |x|+|y| x>y?x:y