I beat my brains out trying to understand that complex math problem.
I was all at sea when trying to solve that complex math problem.
Even the know-everything struggled with that complex math problem.
Good job on solving that complex math problem. I'm impressed.
Beau travail pour avoir résolu ce problème de maths complexe. Je suis impressionné.
He managed to solve that complex math problem in just five minutes. O RLY? That's impressive!
Il a réussi à résoudre ce problème de maths complexe en seulement cinq minutes. Sans blague ? C'est impressionnant !
That complex math problem was beyond one's abilities, so she asked the teacher for guidance.
Ce problème de maths complexe dépassait ses capacités, alors elle a demandé l'aide du professeur.