Answer: Piensan, Pensamos
Step-by-step explanation:
In this short conversation, we have a question with its answer and we have to use the correct form of the spanish verb pensar (to think).
For the first part: ¿Qué ____ hacer ustedes?
Ustedes is the 2nd person in plural you, this means we have to use the form of the verb pensar in present for this subject, which is piensan.
Hence, the complete question is:
¿Qué piensan hacer ustedes?
For the second part: __________ ir a la piscina.
The answer is given with the 1st person in plural nosotros (we), although it is not explicity written, hence the correct form of the verb pensar is pensamos (we think)
Then the complete conversation is:
¿Qué piensan hacer ustedes?
Pensamos ir a la piscina.