# Math Help - sigma notation

1. ## sigma notation

what would be the sigma notation for 5+1+1/5+1/25+1/125. Thanks if anyone could help me out quick that would be great!

2. Originally Posted by tmm
what would be the sigma notation for 5+1+1/5+1/25+1/125. Thanks if anyone could help me out quick that would be great!
$\sum_{n=-1}^{5}\bigg(\frac{1}{5}\bigg)^n=\bigg(\frac{1}{5}\ bigg)^{-1}+\bigg(\frac{1}{5}\bigg)^0+\bigg(\frac{1}{5}\big g)^1+\bigg(\frac{1}{5}\bigg)^2+\bigg(\frac{1}{5}\b igg)^3=5+1+\frac{1}{5}+\frac{1}{25}+\frac{1}{125}$