Please help this a question on edmentum​

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

If f(x) and g(x) are inverse functions of each other, which of the following shows the graph of f(g(x)

(c) the diagram shows the first three shapes of a matchsticks arrangement.first shape = 3second shape = 5third shape = 7given m represents the number of matchstick used to arrange the n'th shape.(i) write a formula to represent the relation between m and n. express m as the subjectof the formula.(ii) 19 matchsticks are used to make the p'th shape. find the value of p.