Question

If $4/5,a,2$ three consecutive term of an $A.P$ then find ${}^{\prime }{a}^{\prime }$

Answer 1

$\frac{4}{5},a,2$ are three consecutive term.

$a_1=\frac{4}{5},a_2=a,a_3=2$

$\therefore$ $a_2-a_1=a_3-a_2$

$\therefore$ $a-\frac{4}{5}=2-a$

$\therefore$ $a+a=2+\frac{4}{5}$

$\therefore$ $2a=\frac{10+4}{5}$

$\therefore$ $a=\frac{14}{5}\times \frac{1}{2}$

$\therefore$ $a=\frac{7}{5}$