The price of each frozen yogurt at a store is $4. a customer pays exactly $30 for x frozen yogurts after a $2 discount. how many frozen yogurts does the customer buy? (is it 7,8,15, or 17 frozen yogurts? also tell me the steps to the prob too? )

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

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?

Are the corresponding angles congruent? explain why or why not.