(a+b+c)∧2等于多少?

2025-12-25 01:32:40
推荐回答(1个)
回答1:

(a+b+c)²
=(a+b)²+2c(a+b)+c²
=a²+2ab++b²+2ac+2bc+c²
=a²+b²+c²+2ab+2ac+2bc