Question

In an A.P, if a3=9 and d=3, find the value of the first term a​

Answer 1

Answer:

option a] 3

Step-by-step explanation:

A3 = a+2d

9 = a+2[3]

a= 9 - 6

a = 3

Answer 2

Answer:

Concept: arithmetic progression is a sequence of series of numbers with a consistent gap of certain value.

Given: a3=9 and d=3.

To find: value of first term.

Step-by-step explanation:

as we know that arithmetic progression  is a series of numbers with a certain  gap  which can be positive and negative.

so, the formulae  of A.P. is $a_{n}=a_{1}+(n-1)d$

here d is the gap  between series of one numbers to that of  the other.

And a means the number in the series of numbers.

so, if we put the values in the formulae , we will get

$a_{n}=a_{1}+(n-1)d$

or, $a_{3} =a_{1} +(3-1)3$

or, $9=a_{1}+2*3$

or, $a_{1} =6-9$

or, $a_{1} =-3$

so, the first term with the gap of 3  is -3

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