[tex]\it = \Big[\dfrac{1}{2}+\Big(\dfrac{7}{9}-\dfrac{^{3)}1}{\ 3}\Big)\cdot\dfrac{9}{2}\Big]\cdot4=\Big(\dfrac{1}{2}+\dfrac{4}{9}\cdot\dfrac{9}{2}\Big)\cdot4= \Big(\dfrac{1}{2}+2\Big)\cdot4=\dfrac{5}{2}\cdot4=10[/tex]
