2 mole of AB(s) is taken in close container of volume of 2 litre. If 1 mole of  AB(s) has taken part in reaction to attain the equilibrium state and equilibrium moles of ${\text{D}}_{\text{2}}\left(\text{g}\right)$   is 0.75.
 $$\begin{gathered} \text{AB}\left(s\right)\rightleftharpoons A\left(g\right)+B\left(g\right)K_C=a{(mol/\mathcal{l})}^2 \\ A\left(g\right)\rightleftharpoons \frac{1}{2}{C}_2\left(g\right)+\frac{3}{2}{D}_2\left(g\right)K_C=b(mol/{\mathcal{l}}^2) \end{gathered}$$
 
at equilibrium  $\left[\text{A}\right]=x\left(\text{mol/litre}\right)\left[{\text{C}}_{\text{2}}\right]\text{=y}\left(\text{mol/litre}\right)$
Calculate the value of $\frac{\text{b}\sqrt{\text{3}}}{\text{a}\left(x\text{+y}\right)}$   is ……