I had to answer the questionsPlease check

¿Qué compraste la semana pasada?
Compré una mochilla la semana pasada.
¿Bailaron Uds.?
Sí, bailamos.

thats correct !

Thank you

¿Qué compraste la semana pasada?

What did you buy last week?
Compré una mochilla la semana pasada.
I bought a backpack last week.
¿Bailaron Uds.?
Did they dance.
Sí, bailamos.
Yes, we danced,
(this depends on what type of spanish, latin american or spanish in spain) if latin american these are correct.

Great job on answering the questions! However, there is a minor mistake in the response to the first question.

Instead of "Compré una mochilla la semana pasada," the correct answer should be "Compré una mochila la semana pasada." You used "mochilla" instead of "mochila," which is the correct spelling.

Keep up the good work! If you have any other questions or need further assistance, feel free to ask.