You can stay here, as long as you keep quiet.

The secret to a clean home isn't hours of sweat and tears. 

As long as you focus on a few key things, your house will be photograph-ready in minutes (so you can get back to doing what you really enjoy). 

You can stay here, as long as you keep quiet.
おとなしくしてさえいれば、ここにいてもよい。

As long as I don't forget my credit card, I'll be O.K. 
クレジットカードさえ忘れなければ何とかなる。

You're welcome to stay as long as you like. 
どうぞごゆっくりしていってください。

This notebook can work as long as 6 hours when powered by internal battery.
このノートパソコンは内蔵バッテリで6時間作動する。