The two operations being represented are subtraction and division. ( subtract 7 from 22, then you have 5x=15, and then divide by 5 to get x=3) to "undo" it you would just use the opposite if each operation (so use addition to add 7 back to 15, and then multiply 5 times 3 to get the original equation on 5x+7=22. I assume you would undo it in the reverse order that you did it the first time. Hope that helped!
