I'd just like to point out (as a former 757 pilot) that those wieights are maximum weights. The average airliner you see passing overhead will be well below the maximum. For example, if the maximum landing weight is 80 tons and the aircraft is on a short flight which will use 3 tons of fuel, there's no point in it taking off at more than 83 tons, even though the maximum permissible take-off weight may be 108 tons. Operating at maximum weight is a rarity in practice.
This does not detract in any way from the excellence of Gandy's answer.