How to solve this summation? from i+1 to n

Question

Can you explain me how to solve this summation?

$$ \sum_{j=i+1}^{n}j $$

I don't know which property to apply, I thought that maybe this one:

$$ \sum_{i=1}^{n}i=$$ $$ \frac{n(n+1))}{2}$$

But it goes from 1 to n, not i+1 to n

Answer 1

Sum from $1$ to $n$ and then minus the sum from $1$ to $i$. This will leave you with the sum from $i+1$ to $n$.