text: I count three commercial zones near here (two contiguous, one not).  If you want to combine two polygons (that both have the same landuse) into one, put on your big mapper pants and do so.  It should take you maybe 30 seconds.
  
  If by "5 member relation of residential areas" (it seems even you can't describe what YOU mean) you are talking about relation/294781 (wow, six digits, that's an OLD relation from 2013) then SAY SO by identifying it with its id#.  If you've read our website, you'd know that sometimes residential landuse (multi)polygons "over describe" details of zoning, like distinctions between medium-density and low-density residential zoning, so the right thing to do is to combine them into one, as OSM doesn't make such distinctions.  This is pretty low-level of noise to have persisted for six years, but that's what happened.  So, get into your favorite multipolygon editor (I don't recommend iD, I recommend JOSM) and use some geometric manipulation to coalesce the polygons (where they are adjacent) into a single polygon with the tag "landuse=residential."  It's called "demultipolygonization" and sometimes it can be done (e.g. if all members are adjacent), sometimes not.
  
  This isn't about me not practicing what I preach as you once again falsely insult me (as you can't seem to not do that in every single changeset comment).  It is about you claiming to want to make the map better, then not.  I don't know if it is because you are poor at editing multipolygons, (I hope the above helps) poor social skills in a shared map project, or both.  But once again:  map well, talk less.