## anonymous one year ago Use the first term (9) and tenth term (45) to find the sum of the first 10 terms. The sequence given is an=4n+5

1. Mertsj

$S _{n}=\frac{n(a _{1}+a _{n})}{2}$

2. Mertsj

Plug and chug.

3. anonymous

uhh what do i plug in? :/ what's sn? and n like specifically what do i plug in :/

4. Mertsj