Finally, substituting into equation (7) gives a definition of B in terms of E.
Once four variables have been defined in terms of the fifth, these values are substituted back into equation (6).
The coefficients in terms of E give the relative amounts of the compounds. All that is left is to assign a value to E. Generally, E is chosen such that all of the coefficients are integers and the greatest common divisor of the set of coefficients is 1. In this case, E must be a multiple of 3 to clear the denominators of the coefficients. However, a value greater than 3 would give coefficients with a greatest common divisor greater than 1. Therefore, E must be exactly 3, and the final equation is
