原配方= A ^ 2 * BA ^ 2 * C + B ^ 2 * CA * B ^ 2 + C ^ 2 *(AB) = ^ 2 * BA * B ^ 2-C(^ 2 B ^ 2)+ C ^ 2 *(AB) = AB(AB)-C(A + B)(A,B)+ C ^ 2 *(AB) =(AB)[C ^ 2-C(A + B)+ AB] =(AB)(CA)(CB)