\(\dfrac{9}{2}-\left[\dfrac{2}{3}-\left(x+\dfrac{7}{4}\right)\right]=-\dfrac{5}{4}\\ \dfrac{9}{2}-\left(\dfrac{2}{3}-x-\dfrac{7}{4}\right)=-\dfrac{5}{4}\\ \dfrac{9}{2}-\dfrac{2}{3}+x+\dfrac{7}{4}=-\dfrac{5}{4}\\ \dfrac{9}{2}-\dfrac{2}{3}+x=-\dfrac{5}{4}-\dfrac{7}{4}\\ \dfrac{9}{2}-\dfrac{2}{3}+x=-\dfrac{12}{4}=-3\\ x=-3+\dfrac{2}{3}-\dfrac{9}{2}\\ x=\dfrac{-18}{6}+\dfrac{4}{6}+\dfrac{-27}{6}\\ x=\dfrac{-41}{6}\)