In this problem, we need to conjugate correctly some verbs in the preterite form. In Spanish, the preterite tense (el pretérito) is used to describe actions completed at a certain point in the past. It is used to talk about beginnings and ends, things that occurred on specific dates or days. So:

1. Ayer nosotros comimos en un restaurante famoso

The right answer is 2) comimos

comimos is the correct conjugation of the regular verb comer for the first-person plural in the preterite form. The Regular Preterite Verb Endings are indicated in the Table bellow. You can recognize only two sets of endings for regular preterite verbs, one for ar verbs and one for both er and ir verbs. To conjugate a regular verb in the preterite tense, remove the infinitive ending (ar, er, or ir) and add the preterite ending that matches the subject. See from the Table that the correct ending here is imos.

Finally, the sentence translates:

We ate at a famous restaurant yesterday

2. ¿Qué compraste tú en el mercado ayer?

The right answer is compraste

compraste is the correct conjugation of the regular verb comprar for the second-person singular in the preterite form. See from the Table that the correct ending here is aste.

Finally, this sentence translates:

What did you buy at the market yesterday?

3. Ayer yo lavé los platos.

The right answer is lavé

lavé is the correct conjugation of the regular verb lavar for the first-person singular in the preterite form. See from the Table that the correct ending here is é.

Finally, this sentence translates:

I washed dishes yesterday