初一计算题:【3(x-y)²】·【-2(x-y)】·【5/4(x-y)】

初一计算题:【3(x-y)²】·【-2(x-y)】·【5/4(x-y)】
初一计算题:【3(x-y)²】·【-2(x-y)】·【5/4(x-y)】

初一计算题:【3(x-y)²】·【-2(x-y)】·【5/4(x-y)】
【3(x-y)²】·【-2(x-y)】·【5/4(x-y)】
=[3(x-y)^2][-2(x-y)][5/4(x-y)]
=[3*(-2)*(5/4)][(x-y)^2(x-y)(x-y)]
=-(15/2)(x-y)^4

【3(x-y)²】·【-2(x-y)】·【5/4(x-y)】
=（x-y）^4（3*(-2)*(5/4))
=-15/2(x-y)^4

中间的运算符号是什么？！