What is the number sense of y=(x-8)2+6

Given the function f(x) = log base 4(x+8) , find the value of f^-1(2)

Can somebody me out with this question

Which of the following represents a number squared is equal to twenty more than nine times that number ? a) x squared = 9x + 20 b) x squared = 20x + 9 c) x squared > 9 + 20x d) x squared = 9 + x + 20