Romania

Can you? Sure. 

A lot depends on how you set them up though. If setup wrong, they can be unstable. 

Reason why is if you set them up using wireless and in mesh (single ssid) mode, then can end up connecting to each other and not back to the main router. Causes all kinds of issues. 

So if you use wireless mesh they shouldn't be able to see each others ssids. 

If they can, one of them needs to have a separate ssid (disabled mesh). 

Or you can hardwire them in and run them in AP mode. that'd work as well. But AP mode disables the smart roaming features of them. So devices tend to be a little "stickier" and not roam as efficiently. 

Or you could do one wireless and one wired. 

Plenty of options. 

You just need to make sure that they aren't daisy chained in wireless

Daisy: router----->extender------>extender

You want star.

Star: Extender<--------router----------->router

And again, far enough apart the extenders can't see each others ssid's (if in wireless extender mode)

If you're not using the single ssid function on the RAX (separate ssid's), its even simpler as you can have one of the EAX's connected to each of t he 5ghz bands.