Time to set it all up…damnnnn

For example if I bought two of these

http://www.guitarcenter.com/Behringer-EUROLIVE-B208D-Active-PA-Speaker-System-106384886-i1449710.gc

and I also own a subwoofer that has xlr connections

so Could I use an RCA to XLR cable with dual XLR outputs with one of my output areas of my mixer ie (it takes red and white end in my NMP then it goes to two speakers)

and then use the other RCA output with another RCA to XLR connection to my SUB?? I am so confused