Question

In certainap the24th term is twice the10th term. Prove that the 72nd term is twice the 34th term

Answer 1

Answer:

here it is!!!

Step-by-step explanation:

Let the first term and the common difference be "a" and "d"

Given.  T24 = 2 T10

      or,  a + 23d = 2(a + 9d)

                        = 2a + 18d

     or,            a = 5d ……………… (i)

Now,     T34     = a + 33d

                 = 5d + 33d                Using (i)

                 = 38d ............. (ii)

        T72     = a + 71d

                 = 5d + 71d                Using (i)

                 = 76d

                 = 2 x 38d

                 = 2 x T34                    Using (ii)

 

                Proved