(x+y)(x-y)-(x的2次方-3xy),其中x等于2,y等于-2分之1

(x-y)3次方.(x-y)2次方.(y-x) 化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/【(x-y)/x】的负二次方 (y-x)²(x-y)+(x-y)的三次方+2(x-y)²(y-x) (y-2x)×(2x-2y)的3次方×(y-2x)的4次方 (x+3y)(x-3y)(x的2次方-9y的2次方） (x-y)的3次方乘(x-y)的2次方乘(y-x) (x-y)的2次方×(y-x)的3次方×（x-y）= 因式分解x次方-y次方+5x-y+6【x-y+2】【x+y+3】 (x-y)的2次方+3(y-x)因式分解 （x-y/x+2y)的3次方 (x-y)的4次方/(y-x)的3次方+(x-y)0的次方*(y-x)+(-x-y)7次方/(x+y)6次方= 化简:【(x-y)的2次方+(x+y)(x-y)】除以2x,其中x=3,y=1.5 (x-y)的5次方-(y-x)的2次方, y=x的-2次方（x {(z+y)(x-y)-(x-y)的2次方+2y(x-y)}除以4y x-y+x+y分之2y的2次方 (x-y)的2次方-2(x-y)+(x-y)-5(x-y) (x-y)的四次方(x-y)-2(x-y)²(y-x）³等于?