Your Nexus uses Android.
That's about Samsung Galaxy and Kindle Fire, but the fact is There IS NO Flash Player for Android and there won't be again.
The instructions at that link may or may not work. They are NOT from Adobe.
I was able to install flash onto my Nexus 7. It worked for me when I tried Amazon Instant on the browser and I tried out some flash games too. This was the tutorial I used: http://nexustabhelp.com/install-flash-nexus-tablet/
I'm still not having any luck getting this installed.