I like to use something called the ICE method:I = initial moles C = Change in molesE = equilibrium moles once you draw the ICE table with the formula on top you simply fill in the blanks. Now remember, in terms of change for products it will always be adding on and for reactants it will always be taking away because in any reaction the reactants decrease and products increase. Finally you must divide all your values by the volume to get concentration as this is what goes into the Kc formula, which is products over reactants. And molecule with a big number in front, will go to the power of that number once in the formula. Once you calculate that it’s simply about getting your units which you can mimic your formula to calculate.