作业帮 > 数学 > 作业

(a +b +c) ^2 +(a -b) ^2 +(b -c) ^2 +(c - a)^2

来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/18 14:05:11
(a +b +c) ^2 +(a -b) ^2 +(b -c) ^2 +(c - a)^2
(a +b +c) ^2 +(a -b) ^2 +(b -c) ^2 +(c - a)^2
(a +b +c) ^2 +(a -b) ^2 +(b -c) ^2 +(c - a)^2
(a +b +c) ^2 +(a -b) ^2 +(b -c) ^2 +(c - a)^2
=(a +b +c) ^2 +a²-2ab+b²+b²-2bc+c²+c²-2ac+a²
=(a+b)²+2(a+b)c+c²+2a²+2b²+2c²-2ab-2bc-2ac
=a²+2ab+b²+2ac+2bc+c²+2a²+2b²+2c²-2ab-2bc-2ac
=3a²+3b²+3c²