This is a linear binomial.
It is linear because 8x is a first degree (8x^{2} would be quadratic or 2nd degree, 8x^{3} is cubic or 3rd degree and so on).
It is a binomial because it contains 2 functions (a linear function: 8x, and a constant function: 5).
I hope that helps! :)
10/28/2013

Rodrigo V.