Hi

I'm working on a textbook mathematical induction problem - part of which involves an algebra simplification that I don't understand.

Just wondering if anyone can explain how they get to the right hand side?

((k-1)(k-1 +1) (2(k-1)+1)) /6 = ((k-1) k(2k - 1)) /6

I don't understand how they managed to ditch so many ks and other numbers.

I don't get algebra at all so the most basic explanation would be good.

Thanks