Adding higher RAM to my laptop with having a non-removable RAM?

Apr 4, 2018
2
0
10
Laptop is Lenovo ideapad 320-15ikb and has a 4gb non-removable RAM, I was thinking of adding more but can I add a bigger RAM like 8gb or something or should I have the same RAM speed? Also I found in a website (http://www.crucial.com/usa/en/advisor) that my laptop can have a maximum RAM of 20gb, can I go 4gb + 16gb? (just an example)

Thanks.