Answer
$${S_{12}} = 222$$
Work Step by Step
$$\eqalign{
& {a_1} = 2,\,\,d = 3 \cr
& {\text{Calculate }}{S_{12}},{\text{ use }}{S_n} = \frac{n}{2}\left[ {2{a_1} + \left( {n - 1} \right)d} \right]{\text{ with }}n = 12 \cr
& {S_{12}} = \frac{{12}}{2}\left[ {2\left( 2 \right) + \left( {12 - 1} \right)\left( 3 \right)} \right] \cr
& {\text{Simplifying}} \cr
& {S_{12}} = 6\left[ {4 + \left( {11} \right)\left( 3 \right)} \right] \cr
& {S_{12}} = 222 \cr} $$
