I'm getting ready for the Olympiads. A week ago the teacher wanted to solve this equation. (as a task). I worked for a week, but I could not do anything.
$$ax^4+bx^3+cx^2+dx+l=0, (a≠0)$$
I know already this equation's solution:
$$ax^2+bx+c=0, (a≠0)$$
What is the difficulty level of this problem? What is the probability to solve this question?
If this question is against MSE rules, I am so sorry.