The chemical equilibrium

Here is a chemical equilibrium:

The initial molarities are given as well as a molarity at equilibrium: In one liter of the reaction mixture, the number of moles of ........... decreased by ........... between the time when the species were mixed (initial state) and the moment when the equilibrium (state balance) has been achieved. Taking into account the coefficients of the reaction , we can now draw up a table of the variation of the number of moles of all species between initial state and equilibrium: ................... Hence the numbers of moles at equilibrium: ................... And finally the equilibrium constant: K = ...................