(a-2b分之2+a-b分之1)*(3a-4b)(a+b)分之a-2b(b-c)(c-a)分之a+b-(a-b)(a-c)分之b+c-(a-b)(c-b)分之c+a

问题描述:

(a-2b分之2+a-b分之1)*(3a-4b)(a+b)分之a-2b
(b-c)(c-a)分之a+b-(a-b)(a-c)分之b+c-(a-b)(c-b)分之c+a