Question

Use the correct form of tener:
Ustedes no __________ hambre.
Ustedes __________ muchos amigos
Use the correct form of the verb ser or estar:
Nosotros __________ felices.
Yo __________ emocionada.
Ellos __________ en la fiesta de quinceañera.

Answer 1

the correct answer it's
ustedes no tienen hambre
ustedes tienen muchos amigos
and the other can be
nosotros estamos felices
yo estoy emocionada
ellos estan en la fiesta de quinceañera

Answer 2

Also you can say: nosotros somos felices.
Nota: "ser" is more permanent, thus:

Nosotros estamos felices (is now, at the moment.

Nosotros somos felices (is always, often)

Answer 3

Yep, nosotros estamos felices would mean we are currently happy, while nosotros somos felices would mean that we are optimistic because we are always happy