Question:
If $\frac{4}{5}, a, 2$ are three consecutive terms of an A.P., then find the value of $a$.
Solution:
Here, we are given three consecutive terms of an A.P.
First term $\left(a_{1}\right)=\frac{4}{5}$
Second term $\left(a_{2}\right)=a$
Third term $\left(a_{3}\right)=2$
We need to find the value of a. So, in an A.P. the difference of two adjacent terms is always constant. So, we get,
$d=a_{2}-a_{1}$
$d=a-\frac{4}{5}$$\ldots(1)$
Also,
$d=a_{3}-a_{2}$
$d=2-a$$\cdots(2)$
Now, on equating (1) and (2), we get,
$a-\frac{4}{5}=2-a$
$a+a=2+\frac{4}{5}$
$2 a=\frac{10+4}{5}$
$a=\frac{14}{10}$
$a=\frac{7}{5}$
Therefore, $a=\frac{7}{5}$