If 6th and 14th terms of an A.P. are 29 and 69 respectively, then its 21st term is

Question

If 6th and 14th terms of an A.P. are 29 and 69 respectively, then its 21st term is

in progress 0
Quinn 4 months 2022-01-06T00:20:49+00:00 1 Answer 0 views 0

Answers ( )

  1. Isabelle
    0
    2022-01-06T00:22:44+00:00
    Reply

    Answer:

    149

    Step-by-step explanation:

    nth term = a+(n-1)d

    6th term = a+(6-1)d=29

                      a+(6-1)d=29

                      a+5d=29 __________eq1

                     

    14th term = a+(14-1)d=69

                      a+(14-1)d=69

                       a+13d=69__________eq2

    eq2-eq1

    a+13d-(a+5d)=69-29

    a+13d-a-5d=40

    8d=40

    d=8

    putting d=8 in eq1

    a+5(8)=29

    a+40=29

    a=29-40

    a= -11

    21th term = a+(21-1)d

                    =-11+(20)8

                     = -11+160

                      =149

Leave an answer

Browse
Browse

18:9+8+9*3-7:3-1*13 = ? ( )