Only #8 and 9 I need your help! Thanks so much!

Prove that if A and B are sets, than A Union A(A Intersection B) = A. Draw a Venn diagram for the symmetric difference of the sets A and B. Section 2.3: Consider these functions from the set of students in a discrete mathematics class. Under what conditions is the function one-to-one if it assigns to a student his or her mobile phone number. student identification number. final grade in the class. home town. Section 2.3: Show that if x is a real number, then [x] - [x] = 1 if x is not an integer and [x] - [x] = 0 if x is an integer. What is the term a_8 the sequence {a_n} if a_n equals an employee joined a company in 2009 with a starting salary of $50,000. Every year this employee receives a raise of $1000 plus 5% of the salary of the previous year. Set up a recurrence relation for the salary of this employee n years after 2009. What will the salary of this employee be in 2017? Find an explicit formula for the salary of this employee n years after 2009. Section 2.5: Determine whether each of these sets is finite, infinite, or uncountable. For any that are infinite, give a one-to-one correspondence between the that set and the set of positive integers. the integers' greater than 10 the odd negative integers the integers with absolute value less than 1,000,000 Section 2.6: Show that matrix addition is commutative; that is, show that if A and B are both m x n matrices, than A+B " B+A. Let A be a zero-one matrix. Show that AVA = A and A^A = A