(b-c)(c-a)分之a-b +(c-a)(a-b)分之b-c +(a-b)(b-c)分之c-a的值能否為0

(b-c)(c-a)分之a-b +(c-a)(a-b)分之b-c +(a-b)(b-c)分之c-a的值能否為0

(b-c)(c-a)分之a-b +(c-a)(a-b)分之b-c +(a-b)(b-c)分之c-a=(a-b)/(b-c)(c-a)-(b-c)/(a-c)(a-b)-(a-c)/(a-b)(b-c)=[(a-b)²;-(b-c)²;-(a-c)²;]/[(a-b)(b-c)(a-c)]=(a²;-2ab+b²;-b²;+2bc-c&…