Hi Yuri,
You could set the OutputSpatialReference of the GeocodeParameters to "SpatialReferences.Wgs84" to get the geographical coordinates
GeocodeParameters gcParams = new GeocodeParameters();
gcParams.OutputSpatialReference = SpatialReferences.Wgs84;
IReadOnlyList<GeocodeResult> results = await localLocatorTask.GeocodeAsync("address", gcParams);
Debug.WriteLine("Latitude: " + results[0].InputLocation.Y + " Longitude: " + results[0].InputLocation.X);
Hope that helps. Thanks
Nagma