Question

If the 9th term of an AP is 15 and the common difference is 2 .find its first term​

Answer 1

Answer:

-1

Step-by-step explanation:

nth term= first term + (n-1)d

9th term= 1st term +8×2

15-16=1st term

1st term= -1

Answer 2

Answer:

-1

Step-by-step explanation:

• Given :    9th term(T9) =  15

               common difference(d) = 2

• To find : First term ( a)

• Formula used : Tn = a + (n-1) d

solution :

              =>    15 = a + ( 9-1)2

              =>  15 = a +16

              =>   15-16 = a

              =>    -1 = a

therefore first term = -1

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