jmc

Expanding the left side of the given equation, we have $2x^2-x-15=14\Rightarrow 2x^2-x-29=0$. Since in a quadratic with equation of the form $a{x}^2+bx+c=0$ the sum of the roots is $-b/a$, the sum of the roots of the given equation is $1/2=\boxed{.5}$.