Question

How do I use summation notation to write the series 2 + 4 + 6 +... for 10 terms?

Answer 1

Since these are even numbers you can represent them by `2n`

And the summation notation then becomes:

`sum_"n=1"^10 2n` for summing 2+4+....+20

If you wanted to do the same for the first 10 odd numbers,
represented by `2n-1`:

`sum_"n=1"^10 2n-1`