What does (−6)−(−7)(−4) equal?

Really need on these. i have no idea what to do

Arestaurant offers a $12 dinner special that has 5 choices for an appetizer, 12 choices for an entrée, and 4 choices for a dessert. how many different meals are available when you select an appetizer, an entrée, and a dessert? a meal can be chosen in nothing ways. (type a whole number.)

Maria walks a round trip of 0.75 mile to school every day. how many miles will she walk in 4.5 days