Question

Mandy☆

求解

Answer 1

✨ 最佳解答 ✨

chou014

(a+b+c)(a+b-c)(a-b+c)(a-b-c)
=(a²+2ab+b²-c²)(a²-2ab+b²-c²)
=(5+2√40+8-7)(5-2√40+8-7)
=(6+√160)(6-√160) →平方差
=6²-√160²=36-160=-124