Is this wrong?

Question

Tienen que hacen las maletas. Salen para Monterrey mañana.

Answer 1

The first sentence is wrong. The infinitive "hacer" must be used instead of "hacen".

Conjugated forms of "tener que" are followed by the infinitive of the following verb.

Answer 2

whenever the word 'que' is used in a sentence and a verb follows it, the verb will always be in the unconjugated form.

Tenemos que IR al parque.
tienen que ESTUDIAR.
tengo que HACER mi tarea.