Ineed to know the answer i’ve been struggling so much

Giuseppi's pizza had orders for $931.00 of pizzas. the prices were $21 for a large pizza, 514 for a medium pizza, and $7 for a small pizza. the number of large pizzas was two less than four times the number of medium pizzas. thenumber of small pizzas was three more than three times the number of medium pizzas. how many of each size of pizza were ordered?

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Write an expression that has three terms and simplifies to 4x - 7. identify the coefficient(s) and constant(s) in your expression