Power to the minus (insert exponent here) is the same as one over power to the absolute value of the exponent, ie the exponent without the minus sign, in this case 1 over 3^2 which is 1/9.
Power to the minus (insert exponent here) is the same as one over power to the absolute value of the exponent, ie the exponent without the minus sign, in this case 1 over 3^2 which is 1/9.
