负3m-n分之9m05+n+3m分之n2等于多少

分类: 作业答案 • 2021-12-29 14:42:09

问题描述：

答

9m²/(-3m-n)+n²/(n+3m)
=n²/(n+3m)-9m²/(3m+n)
=(n²-9m²)/(n+3m)
=(n-3m)(n+3m)/(n+3m)
=n-3m