9. (4 points) The sequence {9n) is defined recursively as follows: 90 = 1 and 9n = 3. In-1 + 2n, for n > 1 Theorem 2. For any non-negative integer n, 9n = .2" - n - - If the theorem above is proven by induction, fill in the blanks below to express what must be es tablished in the inductive step. Fill in each blank with a mathematical equation (i.e., no English). For k > 0, if then