show equations and explain how you are supposed to find alpha and beta

11.2-15 The activity coefficients for a particular binary liq- uid mixture are given by RT ln % = a (1 - ) + 3 (1x); for i = 1, 2 Determine whether a mixture containing 30 mol % of component 1 forms a single, stable liquid phase or two liquid phases at 245 K if the infinite-dilution activity coefficients of the two components at this temper- ature are In = 2.0 and In 2 = 3.0