a2+b2+c2-ab+bc-ac=
2a²+2b²+2c²-2ab+2bc-2ac=0
(a²-2ab+b²)+(b²+2bc+c²)+(a²-2ac+c²)=0
(a-b)²+(b+c)²+(a-c)²=0
a-b=0 b+c=0 a-c=0
(2013+a)的b+c次方
=(2013+a)的0次方
=1
a2+b2+c2-ab+bc-ac=
2a²+2b²+2c²-2ab+2bc-2ac=0
(a²-2ab+b²)+(b²+2bc+c²)+(a²-2ac+c²)=0
(a-b)²+(b+c)²+(a-c)²=0
a-b=0 b+c=0 a-c=0
(2013+a)的b+c次方
=(2013+a)的0次方
=1