Question 11691
Solution :
         (-3a^2b^-2)^2 / (5a^3)^2=
         (-3^2 x a^4 x b^-4)/(5^2 x a^6) = 
          (-3 x -3 x a^4 x b^-4))/(5 x 5 x a^6) =
           9a^4b^-4/25a^6 = (9a^-2b^-4)/25