-2(x-y)的2n次方-4(y-x)的2n-1次方(n为正整数)

-2(x-y)的2n次方-4(y-x)的2n-1次方(n为正整数)
-2(x-y)的2n次方-4(y-x)的2n-1次方(n为正整数)

-2(x-y)的2n次方-4(y-x)的2n-1次方(n为正整数)
-2（x-y）^ 2n -4（y-x）^2n+1
=-2（x-y）^2n +4（x-y)^ (2n+1)
=(x-y) ^2n {2（x-y）-1}
=(2x-2y-1)(x-y) ^2n