roots

By Vieta's Formulas, the sum of roots is $-\frac{b}{a} = -\frac{17}{2}$ and the product of the roots is $\frac{c}{a} = \frac{11}{2}$.

If the roots are a and b, then:

$ab + (a + b) = \text{product of roots} + \text{sum of roots} = -\frac{17}{2} + \frac{11}{2} = \boxed{-3}$