(The 4 subjunctive tenses are, the present subjunctive, the imperfect (past) subjunctive, the present perfect subjunctive, and the pluperfect subjunctive) And now I'm going to assume that this was the rest of the question, if not let me know!
1) Yolanda quiere que tú le "hacer" un favor.
Yolanda quiere que tú le "hagas" un favor.
(Yolanda wants you to do her a favor. So we find the subjunctive tú conjugation of hacer, which is is hagas. And hopefully correcting her grammar was part of that favor.)
2) Si tú "eres" rico, podrías cambiar el mundo.
Si tú "fueras" rico, podrías cambiar el mundo.
(If you were rich, you could change the world. So we find the imperfect subjunctive tú conjugation of ser (eres), which is fueras. When you are rich, you can buy lots of Spanish tutors and maybe bump up that Spanish grade.)
3) Guillermo podría ser el presidente, pero no quiere que le "eligen".
Guillermo podría ser el presidente, pero no quiere que le "elijan".
(Guillermo could be the president, but he doesn't want to be elected. So we find the subjunctive conjugation of elegir (eligen), which is elijan. Let's hope If Guillermo does get elected, he starts lowering these gas prices.)
4) A mi maestra le gustaría que nosotros "aprenden" más rápido.
A mi maestra le gustaría que nosotros "aprendiéramos" más rápido.
(My teacher would like us to learn faster. So we find the imperfect subjunctive nosotros conjugation of aprender (aprenden), which is aprendiéramos. Teachers have such high expectations for us. First they want us to SHOW up to class, now they want us to LEARN faster. I mean come on I don't know how much more I can take.)
5) Mi familia deseaba que Gregorio "llevar" su uniforme en la escuela.
Mi familia deseaba que Gregorio "llevara" su uniforme en la escuela.
(My family wanted Gregorio to wear his uniform to school. So we find the imperfect subjunctive conjugation of llevar, which is llevara. Well what else would Gregorio wear? His bīrthdáy suit?)