\(\dfrac{-17}{12}\cdot\dfrac{-4}{2}\cdot\dfrac{-8}{34}\\ =\dfrac{-17}{12}\cdot\left(-2\right)\cdot\dfrac{-4}{17}\\ =\left(\dfrac{-17}{12}\cdot\dfrac{4}{-17}\right)\cdot\left(-2\right)\\ =\dfrac{4}{12}\cdot\left(-2\right)\\ =\dfrac{1}{3}\cdot\left(-2\right)\\ =-\dfrac{2}{3}\)