Mateo and kristen want to know the combined number of arcade games they played today. they both played 4 games for a dollar, but mateo also won 5 free games. kristen says the combined number is 4m 5 4k, where m is the number of dollars mateo spent, and k is the number of dollars she spent. mateo says the combined amount is 5(m k) 4. who is right? why?