RT RC5300 and RT AC1900P working together

Hello all,

I have a question can you hook these two together in your WiFi system? Would it be better to do it wirelessly or hook them together in your house by Ethernet cable from the first floor to the second floor? Or is this not a good set up for extending your range and WiFi system in your house?

I have Rt Ac5300 set up now as my main router in my house but my office on the second floor is not getting a hard strong WiFi signal in that part of my house.

Thank you all for your help!