a+b+c=0,2a+2b+2c+2ab+2bc+2ac=?

a+b+c=0,2a+2b+2c+2ab+2bc+2ac=?
a+b+c=0,2a+2b+2c+2ab+2bc+2ac=?

a+b+c=0,2a+2b+2c+2ab+2bc+2ac=?
2a+2b+2c+2ab+2bc+2ac
你要问的大约是
aa+bb+cc+2ab+2bc+2ac=吧
aa+bb+cc+2ab+2bc+2ac=（a+b+c）（a+b+c）=0

如果按你题目的话2a+2b+2c+2ab+2bc+2ac=2ab+2bc+2ac=（a+b）c+(a+c)b+(b+c)a=-(a^2+b^2+c^2)
a^2+b^2+c^2+2ab+2bc+2ac=(a+b+c)^2=0

a,b,c都应该有平方吧 如果是结果是0