5. The monthly payment c of a mortgage of n months with monthly interest rater for a principal p is given by the mathematical formula. pr(1 + r)" (1+r) - 1 Write a Java expression to calculate the monthly payment. 6. Let sbe a string of odd length. Write a Java expression to give a substring of s with the center character removed. For example, if sis "Program", the expression should give "Proram". 7. Let s be a string of length at least 2. Write a Java expression to give a string with the first and last characters of s swapped. For example, if s is "dog", the expression should give "god". 8. Let si and s2 be two strings of even lengths. Write a Java expression to combine the first half of si and the second half of s2, if s1 is "Computer and s2 is "Programmer", the expression should give "Compammer" 9. A string variable fullName represents a full name such as "Doe, John". Write a Java expression to give a string of first initial and last name, e.g., "). Doe