Answer :

Given:

The explicit rule for a sequence is given as:

[tex]f(x)=1.25n+6.25[/tex]

The given specific term is 25.

The aim is to find the position of the term 25.

The position of the term 25 is given by the value of n when f(n)= 25.

Therefore,

[tex]\begin{gathered} f(n)=25 \\ 1.25n+6.25=25 \\ 1.25n=25-6.25 \end{gathered}[/tex]

Solving further,

[tex]\begin{gathered} 1.25n=18.75 \\ n=\frac{18.75}{1.25} \\ n=15 \end{gathered}[/tex]

Hence, the position of term 25 is 15.