## College Algebra (6th Edition)

$4,8,12,16,....400$ $S_{100}= 20200$
Sequence: $4,8,12,16, ... 400$ $S_{100} = 4+8+12+....+400$ Sum of $n$ terms, $S_{n}= \frac{n}{2}(a_{1}+a_{n})$ $S_{100}= \frac{100}{2}(4+400)$ $S_{100}= 50(404)$ $S_{100}= 20200$