exercise 3 please

Show all work. Neatness counts! Exercise 1. Show that for an integer n the numbers n and n have the same last digit. Exercise 2. Prove that if ged(a,m) = 1 and goda - 1, m) = 1 then + am)-1 = 0 (mod m). Exercise 3. Write a function in C++ that takes as input two integers a and m and returns a' (mod m) if it exists or says "no inverse" if it does not. You may need to install an arbitrary precision package to accomodate large numbers. Exercise 4. Write a C++ function that takes as input a pair of integers (a, n) and a text file that has been converted to number blocks of a fixed size and returns m" (mod n). You may need to install an arbitrary precision package as there are limits to standard C++ number sizes