Question

What is the solution for f(n)=1.25n+6.25; 25???
By using explicit rule!

Answer 1

f(n) = 1.25n + 6.25
25 = 1.25n + 6.25
25 - 6.25 = 1.25n
18.75 = 1.25n
18.75/1.25 = n
15 = n

Answer 2

n = 15

Explanation:

The given explicit formula is f(n) = 1.25n + 6.25

In which n represents the number of term of the sequence

If f(n) = 25

Then 25 = 1.25n + 6.25

Now we subtract 6.25 from both the sides of the equation.

25 - 6.25 = 1.25n

1.25n = 18.75

Further we divide this equation by 1.25

`(1.25n)/(1.25)= (18.75)/(1.25)`

n = 15

Therefore, n = 15 is number of term.