for an A.P. t17=54 and t9=30 then find the first term a and common difference d​

1 thought on “for an A.P. t17=54 and t9=30 then find the first term a and common difference d​”

1. Answer:

   a = 6

   d = 3

   Step-by-step explanation:

   t 17 = 54

   t 17 = a + (n-1) d

   54 = a+(17-1)d

   54 = a + 16d..(1)

   t9 = 30

   t9= a + (n-1) d

   30 = a+(9-1)d

   30=a+8d..(2)

   1 – 2

   8d = 24

   d = 24/8

   d = 3

   put d = 3 in (2)

   30 = a + 8(3)

   30 – 24 = a

   a = 6

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