Hey there! I'm happy to help!
[tex]a^-^2[/tex] is the same thing as 1/a². So, [tex]5^-^2[/tex] is 1/25. This is multiplied by 3² which is 9, so this is 9/25.
In the denominator, we have [tex]5^-^1[/tex], which is 1/5. We multiply this by 3, which is 3/5.
So, we divide 9/25 by 3/5, giving us 3/5.
Now, we raise this to the power of -2, so we flip the numerator and denominator and then square both numbers, giving us 25/9.
Have a wonderful day! :D