Escribe esta oración en el pretérito: 1. él va a madrid el lunes2. ella hace sus maletas para ir de vacaciones.3. ud. toma el ave en la estación atocha.

Each of this sentences are given in the simple present tense. This tense is used to talk about habitual actions or routines. This tense is also used to describe things that happen now or in the near future. So we need to rewrite them in the preterite tense. The preterite tense is one of two simple past tenses. It is used to describe actions that took place or were completed at a certain point in the past. Accordingly:

The sentence Él va a Madrid el lunes changes to Él fue a Madrid el lunes. As you can see, we only change the word va into fue. So both words comes from ir that is an Spanish irregular verb that translates into to go. So these sentences stand for the third person singular and the conjugation of the verb ir that matches this person in the simple present is va and for the preterite tense is fue.

The sentence Ella hace sus maletas para ir de vacaciones to Ella hizo sus maletas para ir de vacaciones. Here we change the word hace into hizo. So both words comes from hacer that is an Spanish irregular verb that translates into to pack in this context. So these sentences stand for the third person singular and the conjugation of the verb hacer that matches this person in the simple present is hace and for the preterite tense is hacer.

The sentence  Ud. toma el AVE en la estación Atocha to Ud. tomó el AVE en la estación Atocha. Here we change the word toma into tomó. So both words comes from tomar that is an Spanish irregular verb that translates into to take. So these sentences stand for the second person singular (formal you) and the conjugation of the verb tomar that matches this person in the simple present is toma and for the preterite tense is tomó.