Which expression is equivalent to (5^-2)(5^-1)

The rule for multiplying similar bases with exponents:

(a^b)(a^c)=a^(b+c)

In this case we have:

(5^-2)(5^-1)

5^(-2-1)

5^(-3)

The rule for negative exponents:

a^(-b)=1/(a^b)

So in this case:

5^(-3) is equal to 

1/(5^3)

1/125

Dagriculture is the answer -explanation-