Which describes this type of series?
-20 - 18 - 15 - 11 …
I think it is both arithmetic and geometric
differences of 2 , 3 , 4 so not arithmetic
-20
**** +2
-18
**** +3
-15
**** +4
-11
is it of form g + g r + g r^2 ....+gr^(n-1) ?
-20 ( 1 + r + r^2 + .... r^(n-1) ) ?
no way