Computer Doesn't have a mic jack?

I have a lenovo laptop running windows 8 and it doesn't have a mic jack. I was wondering how I would use my mic on my turtle beachs' x12. They have two cables one for audio and the other for the Mic, but I don't know how I would use them… Please help Thanks in advance

Some laptop jacks are double--headphones and microphone. See the "Lenovo laptop" user guide, whichever one it is. You can buy an adapter that accepts both plugs, ends in one.
If that is not the case for your laptop model, then you can get a USB audio adapter with lots of connectors.