Get Value from key using linq

Why do you want to get a value from a Dictionary using LINQ? You can just get the value using:

int value = dictionary[key];

You could use Single, but it's totally pointless and more code:

var keyValuePair = dictionary.Single(x => x.Key == key);
int value = keyValuePair.Value;

Why use Linq for something that is built in?

var val = myDict[key];

Use Linq where it makes sense (querying collections), not for something that is already well handled by the Dictionary classes.