Give a recursive definition for strings of properly nested parentheses and curly braces. For example ({}){}() is properly nested but ({)} is not.

How would you categorize the software that runs on mobile devices? break down these apps into at least three basic categories and give an example of each.

If you're using an existing powerpoint presentation that will receive new slides based on a word outline, select the a. slide that will appear after the new slides. b. first slide in the presentation. c. slide that will appear before the new slides. d. last slide in the presentation.

File account.java (see previous exercise) contains a definition for a simple bank account class with methods to withdraw, deposit, get the balance and account number, and return a string representation. note that the constructor for this class creates a random account number. save this class to your directory and study it to see how it works. then write the following additional code: 1. suppose the bank wants to keep track of how many accounts exist. a. declare a private static integer variable numaccounts to hold this value. like all instance and static variables, it will be initialized (to 0, since it’s an int) automatically. b. add code to the constructor to increment this variable every time an account is created. c. add a static method getnumaccounts that returns the total number of accounts. think about why this method should be static - its information is not related to any particular account. d. file testaccounts1.java contains a simple program that creates the specified number of bank accounts then uses the getnumaccounts method to find how many accounts were created. save it to your directory, then use it to test your modified account class.