问题描述: (2m+3n)(2m-3n)-(3m-2n)(3m+2n) 1个回答 分类:数学 2014-12-15 问题解答: 我来补答 (2m+3n)(2m-3n)-(3m-2n)(3m+2n)=(4m²-9n²)-(9m²-4n²)=4m²-9n²-9m²+4n²=-5m²-5n² 展开全文阅读