like terms are numbers or variables(or both together) the like terms in here are k2 -5k2 and -5k2 and the pther set of like terms are yp-4 and yp-4 when you add these you are supposed to get 2yp-4 -9k2 +p-4+y you are left with the y and p-4 alone and dont add anything becaus you can't, so that should eb your answer
Hope this helps
