I have problems with two questions on math homework:

1. Prove the following statement. If x is an even integer, then 4x+5 is an odd integer. (using format x = some k and so on)

2.Let A = {a1, a2} and B = {b1, b2, b3}. Let the function f:A B be given by the following set of ordered pairs: f = {(a1,b2),(a2,b3)}. (10 points)

List as a set of ordered pairs a function g:B A with the property that for all a in A g(f(a)) = a, and show that this property holds. HINT: Think of g as undoing what f does.