From the graph we know that this polynomial has two zeros; one in x=5 and one in x=8. Now, since we know that this happens we have to remember that a polynomial can be factor as:
[tex]y=(x-r_1)(x-r_2)\cdot\cdot\cdot(x-r_n)[/tex]
where the r's are the zeros of the polynomial.
Therefore in this case we have:
[tex]y=(x-5)(x-8)[/tex]
