[-2(X-y)²]².（y-X）³

[-2(X-y)²]².（y-X）³

[-2(X-y)²]².（y-X）³
=-4（x-y）^4 × （x-y）^3
=-4（x-y）^7

=4(x-y)的4次方 ×[-(x-y)的3次方]
=-4(x-y)的7次方

[-2(x-y)²]².(y-x)³
=-4(x-y)⁴ · (x-y)³
=-4(x-y)⁷