Hello,

These problems are so easy but I am making it too hard... I can get everything up to the proof part, which is underlined below

his is not too hard: 1 + 2 + ... + k + (k+1) = k(k+1)/2 + (k+1) =(k(k+1) + 2 (k+1))/2 = (k+1)(k+2)/2.The first equality is a consequence of the inductive assumption.

I know this is "factoring out the k+1" but I dont understand what that means.... could someone explain or break it down? Thanks!!