Answers:
SARA Hoy podemos hacer unas diligencias.
JOSÉ Sí, (1)hagámoslas.
SARA Primero vamos a cobrar el cheque.
JOSÉ Sí, (2)cobrémoslo.
SARA Después, vamos a enviar los paquetes para mi madre.
JOSÉ Sí, (3)enviémoslos.
SARA Después del correo, vamos a visitar a mi prima
Rosa. JOSÉ Sí, (4)visitémosla.
SARA Y para terminar, vamos a la zapatería.
JOSÉ No, no (5)vayamos. Prefiero ir al centro comercial.
Translation
SARA Today we can do some assignments.
JOSÉ Yes, let's do them.
SARA First we will cash the check.
JOSÉ Yes, let's get it.
SARA Next, we will send the packages to my mother.
JOSÉ Yes, let's send them.
SARA After the mail, we are going to visit my cousin Rosa.
JOSÉ Yes, let's visit her.
SARA And finally, we will go to the shoe store.
JOSÉ No, let's not go. I prefer to go to the mall.
Explanation: the subject in all these sentences is "Sara and José", that is first-person in the plural.
In transitive verbs, when we add a direct object pronoun to affirmative imperatives, it has to agree in gender and number with the direct object and is added at the end of the verbal form.
(1) hacer (transitive) (direct object = las diligencias)
(1) hagamos unas diligencias => hagámoslas (diligencias = feminine and plural)
(2) cobrar (transitive) (direct object = el cheque)
(2)cobremos el cheque => cobrémoslo (cheque = masculine and singular)
(3) enviar (transitivo) (direct object = los paquetes)
(3)enviemos los paquetes => enviémoslos (paquetes = masculine and plural)
(4) visitar (transitive) (direct object = Rosa)
(4)visitemos a Rosa => visitémosla (Rosa = feminine and singular)
In non-transitive verbs there is no direct object. If there is an indirect object its indirect object pronoun can be placed before the verb.
(5) ir (non-transitive) (indirect object = a la zapatería)
(5)no vayamos a la zapatería => no vayamos (without pronoun)