Ineed to show work for this problem but i have hw answer i just need to know what work to write number 18

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?

Anyone know? is appreciated! will mark brainliest if correct!

What are the steps to solving the inequality 3b + 8 ≥ 14?