what is 5 to the power of negative 2
when a number is to a negative power it is equal to 1 over that number to a positive power,
ex:
$${{\mathtt{5}}}^{-{\mathtt{2}}} = {\frac{{\mathtt{1}}}{{{\mathtt{5}}}^{{\mathtt{2}}}}} = {\frac{{\mathtt{1}}}{{\mathtt{25}}}}$$