långt is an adverb here (you can tell because it modifies an adjective: långt bort). Adverbs can have many different endings but -t is the most common one.
Now I know why the Swedish chef tossed away his cooking utensils upon saying "bort, bort, bort"
Åka is a very wide word for to go in general and it can include ’to drive’. But a more specific word for ’to drive’ is köra.
I wanted to know this too! It gave the right answer as ¨We DRIVE far away¨.
It is bort if you are indicating travel. For instance, if I were to say, "He is gone," I would say, "Han är borta." On the other hand, if I were to say, "He is going away," I would say, "Han åker bort." Another example is this: "Where are you?" In Swedish, this would be, "Var är du?" "Where are you GOING?" would be "Vart ska du?" This rule is the same principle that applies to 'hit' and 'här'. (Jag är här. Jag kom hit.)