Cuida es la diferencia entre una variable cualitativa y una variable cuantitativa​

Ms.ortiz sells tomatoes wholesale. the function p(x)=-80x^2+320x-10, graphed below, indicates how much profit she makes on a load of tomatoes if she makes on a load of tomatoes if she sells them for 4-x dollars per kilogram. what should ms.ortiz charge per kilogram of tomatoes to make on a load of tomatoes?

Answer! if you don’t mind, can you explain

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?