と考(かんが)えられているIs considered, Is thought of as

と考えられる and と考えられている are similar but differ slightly in nuance. と考えられる means 'it can be considered (A)' and implies a basis in evidence or reasoning. On the other hand と考えられている suggests something is a commonly held belief or consensus, like the English 'it is (generally) thought that (A)'.

とされている and とかんがえられている both mean 'It is believed/considered (A)' and are used to present ideas objectively. Both make statements sound more neutral or widely accepted, often in formal writing, academic papers, or news reports.

These two forms of the verb 考える express opposite sentiments. 考えられない (lit. 'one cannot think') expresses strong disbelief or the idea that something is inconceivable, e.g. 'そんなことは考えられない' ('I can't imagine such a thing'). In contrast, と考えられている indicates a commonly accepted or reasoned belief, often used in formal writing to make statements less direct, e.g. 'これは効果的だと考えられている' ('This is considered effective').

といわれている 'it is said' and とかんがえられている 'it is thought' both soften a statement and make it feel more objective or widely accepted. This can make an idea sound more trustworthy or backed by others. Both are formal and common in writing.

～は～となっている and と考えられている both express current states or views, but differ in tone. ～は～となっている describes some sort of established fact that is now 'the way things are', e.g. 店は日曜休業となっている ('The store is closed on Sundays'). と考えられている expresses a generally held belief or reasoning and is often used to make a statement sound less direct, e.g. 彼は天才だと考えられている ('He is thought to be a genius').