Question

Find Sn for the given arithmetic series a1=-26 d=-9 n=24

Answer 1

Answer:

- 3108

Step-by-step explanation:

The sum to n terms of an arithmetic series is

$S_{n}$ = $\frac{n}{2}$ [ 2$a_{1}$ + (n - 1)d ]

Substitute the given values into the formula

$S_{24}$ = $\frac{24}{2}$ [ (2 × - 26) + (23 × - 9) ]

                          = 12 ( - 52 - 207 )

                         = 12 × - 259 = - 3108