作业帮(a²+b²+c²）-1/2[（a-b)²+(b-c)²+（c-a）²]其中a=1/2,b=-2/3,c=-3/4
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/29 20:15:27
![(a²+b²+c²）-1/2[（a-b)²+(b-c)²+（c-a）²]其中a=1/2,b=-2/3,c=-3/4](/uploads/image/z/3148332-60-2.jpg?t=%28a%26%23178%3B%2Bb%26%23178%3B%2Bc%26%23178%3B%EF%BC%89-1%2F2%5B%EF%BC%88a-b%29%26%23178%3B%2B%28b-c%29%26%23178%3B%2B%EF%BC%88c-a%EF%BC%89%26%23178%3B%5D%E5%85%B6%E4%B8%ADa%3D1%2F2%2Cb%3D-2%2F3%2Cc%3D-3%2F4)
(a²+b²+c²）-1/2[（a-b)²+(b-c)²+（c-a）²]其中a=1/2,b=-2/3,c=-3/4
(a²+b²+c²）-1/2[（a-b)²+(b-c)²+（c-a）²]其中a=1/2,b=-2/3,c=-3/4
(a²+b²+c²）-1/2[（a-b)²+(b-c)²+（c-a）²]其中a=1/2,b=-2/3,c=-3/4
(a²+b²+c²）-1/2[（a-b)²+(b-c)²+（c-a）²]
=(a²+b²+c²）-1/2(2a²+2b²+2c²-2ab-2bc-2ca)
=a²+b²+c²-a²-b²-c²+ab+bc+ca
=ab+bc+ca
=1/2×(-2/3)+(-2/3)/(-3/4)+(-3/4)/(1/2)
=-1/3+1/2-3/8
=1/24×(-8+12-9)
=-5/24