Answer:
a1 = 17
an+1 = an +0.5
Step-by-step explanation:
Let
n ----> the number of months
A ---> the length of Janina's hair
we know that
The linear equation in slope intercept form is equal to
[tex]A=mn+a_1[/tex]
where
m is the slope or unit rate
a_1 is the initial value or y-intercept
In this problem we have
[tex]m=0.5\ in/month[/tex]
[tex]a_1=17\ in[/tex]
substitute
[tex]A=0.5n+17[/tex]
This equation can be expressed as
[tex]a_n_+_1=a_n+0.5n[/tex]
where
[tex]a_1=17[/tex]