The correct answer by me is: If you are looking for the easy way out, and not a deeper understanding, it is cheating. The answer is big NO! BRAINLY app is just a simplified version of online forums (e.g.Quora) but it is only used for SCHOOL STUFFS (off-topics is not allowed on this app).
The title of my answer is Is it considered cheating to use websites like Brainly
My answer's reference is Quora