The talk will be rounded up by recommendation and solution.對不對?

round up 一般用於一個"活動"或"集合作結"，我估計你是想說"總結"或"結束的最後項目。

意思上跟round up的一般用法不太配合，除非你的"Talk"當中要求在場人士分組討論，然後你的"結束程序是要求把各組的意見分享而作出歸納或總結，這詞彙才合理。

假如只是你自己一個"演說"一套講論分析或報告研究的建議和解決方案，應該是說：
The talk will be concluded with recommendation and solution.
留意是前置詞是用"with"，不是by。因為recommendation和solution並不是"主動人"或"主動物"，它們不能成為"某程予"或"某演說"中作出結論/結束，講說的是你(人)表示演說作結是"包含"這兩個內容。

recommendation=suggestion=make a suggestion,comment,remark.
solution=A solution immediately suggested itself to me=I immediately thought of a solution, as it has been suggested.
Change to "suggestion"and remarks better.