If you are going shopping the least you can do is "anunciar una liquidación". This can be used for a brand or shop to communicate that prices are reduced so that would not depend on the buyer. The rest of the sentences correspond to the one who is buying or wants to buy.
Answer:
utilidad , factibilidad , precision , propreidad
Explanation:
The model you gave is a little unclear, but I think it would be:
1) Ricardo voy a preparar su tarea a las ocho y cuarto.
2) Isabel y Ricardo van a cenar a las nueve.
3) Isabel voy a ver la television a las nueve y treinta y cinco.
4) Ricardo voy a caminar con el perro a las diez menos cuarto.
