isabelle/valid/amc12a_2015_p10.thy (14 lines of code) (raw):
(*
Authors: Albert Qiaochu Jiang
*)
theory amc12a_2015_p10 imports
Complex_Main
begin
theorem amc12a_2015_p10:
fixes x y:: nat
assumes h0: "0<y"
and h1: "y<x"
and h2: "x+y + (x*y) = 80"
shows "x=26"
sorry
end