How do you balance this redox reaction?

MnO4- ------> Mn2+ , first balance manganese atoms .It is balanced. Add water molecules for each deficient O atom on other side. Add H+ ions (required) to the deficient side. MnO4- .Since MnO4- is oxidising agent add required electrons on left side to balance the charge on right side.MnO4- + 8 H+ + 5 e- -----> Mn2+ + 4 H2O . On the similar lines balance SO3 ^2- --------> SO4 ^ 2- .This gives SO3 ^ 2- + H2O -----> SO4 ^ 2- + 2H+ + 2 e- Multiply the first equation by 2 and multiply the second equation by 5 and add the two equations.All other ions in the redox reaction are spectator ions.This is the method to balace ionic equations in acid medium. In basic medium add required OH- ions on both sides to neutralise H+ ions.