A 10X TBE solution is 10 times as concentrated as a 1X TBE solution, which means that you must dilute it 10-fold to get it to match a 1X TBE solution.
Since the solution will have various components of different molarities,
This is usefull when you're not concerned about the individual components of the solution, but rather about how concentrated or diluted a solution is.
So, you're basically dealing with a dilution calculation
In you case, you'll get
This will be the final volume of the solution, which means that the volume of buffer you must add is