Question

if sum of 3 consecutive yerms of an ap is 21 find its first term​

Answer 1

Answer

==>

First term of AP will 7

Given

==>

Sum of 3 consecutive terms of AP = 21

Solution

==>

Let the consecutive terms of AP as

a-d , a , a+d

✯We don't take a , a+d , a+2d as ap sequence because in such type of questions we should use the form mentioned above.

So from above sequence we got

a (1st term of AP) = a

d (common difference) = d

Calculation

So adding these three terms we got:

a-d +a +a+d = 21

here -d will cancelled out from +d

=>a + a + a = 21

=>3a. = 21

=>a. = 21/3

=>a. = 7

So we get the value of a which is 7