Mr. Ledger buys a box of 24 donuts for a lesson in his math class about circumference. Write an equation for the number of donuts y that are left at the end of the day when x donuts are used during the lesson.
Last year, Mr. Ledger used donuts during the lesson. This year, he used 22donuts.
Place points on the graph to show how many donuts are left at the end of last year's lesson and this year's lesson.