Which line has a constant of proportionality between y and x of 5

How do businesses a country's economy? a. by investing in goods and services b. by increasing the unemployment rate c. by making profits

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

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?