\(\Leftrightarrow x-\left[\dfrac{11}{2}-\left(-\dfrac{9}{21}+\dfrac{35}{21}\right)\right]=-\dfrac{1}{3}\\ \Leftrightarrow x-\left[\dfrac{11}{2}-\dfrac{26}{21}\right]=-\dfrac{1}{3}\\ \Leftrightarrow x-\dfrac{179}{42}=-\dfrac{1}{3}\\ \Leftrightarrow x=\dfrac{55}{14}\)