Question

find the sum of series 1*2+2*3+3*4+. . .152*153+153*154

Answer 1

\[\Huge \sum_{n=1}^{153}n(n+1)\]

Answer 2

Thanks got to that part. How do u sum that expression?

Answer 3

Use distributive property.

Answer 4

\[\Huge \sum_{n=1}^{153}n^2 + n = \sum_{n=1}^{153} n^2 + \sum_{n=1}^{153}n\]

Answer 5

Thanks that gives
\[(\frac{ 1 }{ 6} N (2N+1)+(N+1))+(\frac{ 1 }{ 2}N(n+1))\]