Exponents: 5^2a^2b divided by b^3 and the exponent for all this is -2.?

[(5^2a^2b)/b^3]^-2 (apply the -2 exponent to every value in the numerator and denominator; when applying an exponent to an exponent, multiply them)

(5^-4a^-4b^-2)/b^-6 (switch negative exponents from their spot (numerator to denominator / denominator to numerator) to change them positive)

b^6/(5^4a^4b^2) (divide b^6 by b^2, which is the same as subtracting 2 from 6; apply the exponent to 5)

b^4/(625a^4) <===ANSWER

( 5^2 * a^2 * b / b^3) ^ -2

( 25*a^2 / b^2) ^ -2

The negative flips the fraction

(b^2 / 25a^2)^2

(b^4 / 625a^4)

[5^2a^2b/b^3]^-2

[25a^2/b^2]^-2

b^4/625a^4