Question

find the sum of the 18 th term of of the AP 4,-1, -6​

Answer 1

Answer:

In given AP

first term(a) = 4

common difference(d) = -6 -(-1 ) = -1 -(4) = -5

18 th term of of the AP 4,-1, -6​ = a + 17d

      18 th term of of the AP = 4 + 17 ×-5

                                               = 4 +(-85)

                 = 4-85

                 = -81