Question

a的平方-2a(b+c)+(b+c)的平方 分解因式

希望大家可以不要一下子就得出答案，最好写一下步骤喔，thank you very much.

Answer 1

把（b+c)当成一个整体，
=[a-(b+c)]^2
=(a-b-c)^2
实在不明白，不妨设b+c=x
a^2-2ax+x^2
=(a-x)^2
再换回来
=[a-(b+c)]^2
=(a-b-c)^2

Answer 2

a²-2a(b+c)+(b+c)²
=[a-(b+c)]²
=（a-b-c）²