(*
  Authors: Wenda Li
*)

theory amc12b_2021_p9
  imports Complex_Main
begin

theorem amc12b_2021_p9:
  shows "(ln 80 / ln 2) / (ln 2 / ln 40) - (ln 160 / ln 2) 
            / (ln 2 / ln 20) = (2::real)"
  by sorry

end