Question

How do you use summation notation to write the arithmetic series `-3.9+(-1.9)+.1+...` for six terms?

Answer 1

`sum_(n=0)^5(-3.9+2n)=6.6`

Explanation:

`sum_(n=0)^5(-3.9+2n)=-3.9*6+2sum_(n=0)^5n=`
`=-23.4+2*(5(5+1))/2=-23.4+30=6.6`