Question

show that 2.3+3.4+4.5+..........upto n terms= n(n^2+6n+11)/3​

Answer 1

Hey guys ,
The question is
2•3+3•4+4•5+...........

First series (1)
2+3+4+......
= n(n+1)/2

Second series (2)
3+4+5+......
= n(n+1)/2