Can anyone help me solcing these excercises please?
a. Prove that 1*2+2*3+...+n(n+1)=[n(n+1)(n+2)]/3
Ok, i understand. I am sorry, actually these are from my homework (the easier ones), but have no idea how to start. Maybe at a. I should prove for P(1), then for P(n+1)? Then it will be 1*2+2*3+...+(n+1)(n+2) ?
For b. I have no idea what should I do