An=-2+5(n-1)
to convert this to function notation we need to simplify the expression and the equalize the expression simplifyed to f(n)
[tex]-2+5(n-1)=-2+5n-5=5n-7[/tex]in the middle step we applied the distributive law for the multiplication, and the we operate the independent terms
then
f(n)=5n-7