найжи лишнее слово в прелложении it was founded in 1152 by Prince Yuri Dolgoruky and is one of the most oldest cities in Russia.

Лишнее слово: most.

Правильно: "it was founded in 1152 by Prince Yuri Dolgoruky and is one of the oldest cities in Russia."
(Здесь не должно быть сочетания "most oldest"; либо "oldest", либо "most ancient".)