Question

Show that the series ∑−2∞=1 is convergent.​

Answer 1

Answer:

Show that the series

∑n,m=1∞1(n+m)!

is absolutely convergent and find its sum.

This comes from a chapter called interchange of limit operations. I tried using the ratio test but wasn't sure if this was the correct route.

Answer 2

Answer:

i think ubove answer is the right answer