painful / イタい: (slang) cringy; embarrassing

not hard to, easy to, is obvious that

untie; unravel; undo (a fastening); unwrap / dispel (doubts); clear up (a matter)

solve (a problem); answer (a question); unravel (a riddle) / comb; untangle (hair)

pain

(archaic) difficult

question, problem on homework etc. / a question; a matter (of time etc.) / a problem (something that needs to be dealt with); a trouble / an issue; a matter

difficult

difficult or hard to do (emphasis on the disagreeability of performing the action)

difficult or hard to do