Hello I am a university student working my way through a computer science degree but halfway I gave up my studies to focus on personal problems and now that I am back I struggle even with basic things because I lost touch with the basics for a long period of time and now that I am back to studying I am having a hard time continuing from where I left of and I feel so helpless and embarrassed when I find myself stuck to something so simple, if someone can explain to me the steps that took place and maybe have some recommendation how to refresh the basics or have a reference somewhere that I can lookup basic knowledge to understand the steps in a solution, that would be really helpful, thank you.

n(n+1)(2n+1)+6(n+1)\^2=

=(n+1)\[n(2n+1)+6(n+1)\]