1. The problem states Marcos spent 8.15 total on a drink and a sandwich. 2. The drink cost 1.29, so the sandwich cost is represented by $x$. 3. The equation given is $x + 1.29 = 8.15$. 4. To find $x$, subtract 1.29 from both sides: $$x + \cancel{1.29} = 8.15 - \cancel{1.29}$$ $$x = 6.86$$ 5. Marcos spent 6.86 on the sandwich. 6. The sandwich options are 4.17 (ham), 3.87 (turkey), and 3.41 (tuna). 7. None of these prices match 6.86, so there might be a misunderstanding or error in the options. 8. However, if the question is which sandwich price fits the equation $x + 1.29 = 8.15$ exactly, none do. 9. If the question is which sandwich Marcos likely bought given the total and drink price, the sandwich cost is 6.86, which is not listed. Final answer: Marcos did not buy any of the sandwiches listed based on the equation and prices given.