what is the sum of the arithmetic series 18 t=1 (3t-4)a. 234b. 441c. 25.5d. 49

The given arithmetic series is[tex] \sum_{t=1}^{18} (3t-4) [/tex]When t =1, we will get the first term,a, which is[tex] 3(1)-4 =3-4=-1 [/tex]When t =18, we will get the last term,l , which is [tex] 3(18)-4 = 50 [/tex]Now we use the formula of sum of n terms which is[tex] S = \frac{t}{2} (a+l) [/tex]Substituting the values of t,a and l, we will get[tex] S = \frac{18}{2} (-1+50) = 9*49 =441 [/tex]