问题
填空题
计算:(a-b-c)2=______.
答案
原式=[(a-b)-c]2
=(a-b)2-2(a-b)c+c2
=a2-2ab+b2-2ac+2bc+c2
=a2+b2+c2-2ab-2ac+2bc.
故答案为:a2+b2+c2-2ab-2ac+2bc.
计算:(a-b-c)2=______.
原式=[(a-b)-c]2
=(a-b)2-2(a-b)c+c2
=a2-2ab+b2-2ac+2bc+c2
=a2+b2+c2-2ab-2ac+2bc.
故答案为:a2+b2+c2-2ab-2ac+2bc.