Answer:
S28 = 28/2 (5+248)
Step-by-step explanation:
The sum of an arithmetic series is given by
Sn = n/2 ( a1 + an)
n = 28
We need to find the first and last terms
a1 = 9(1) -4 = 5
a28 = 9(28) -4 =248
=14 *(253)
3542
