According to the definition, when a+b = 2, it is said that A and B are related to the equilibrium number of 1. If X and x-3 are related to the equilibrium number of 1, then according to the definition, x-3+X = 2, so X = 2-(x-3) = 5-X. Therefore, X-.

The balance number is indicated by the symbol "k". Theoretically, all reactions have inverse reactions, that is, all reactions have thermodynamic equilibrium and equilibrium constants. The larger the equilibrium constant, the more thorough the reaction. The value of equilibrium constant can only roughly tell us the maximum degree of forward reaction of reversible reaction, but it can't predict the time required for the reaction to reach equilibrium. In addition, for the reaction with small equilibrium constant, it shows that the positive reaction is impossible under this condition.