Question

Find the sum of first 25 terms of an ap whose end term is 1 - 4 n

Answer 1

Answer:

-1275

Step-by-step explanation:

nth term=1-4n

1st term=1-4*1

            =-3

25th term=1-4*25

               =1-100

                 =-99

sum of 25 terms=25/2{-3+(-99)}

                          =25/2{-102}

                           =25*-51

                             =-1275