25b ÷5bc =

$${\frac{{\mathtt{25}}{\mathtt{\,\times\,}}{\mathtt{b}}}{\left({\mathtt{5}}{\mathtt{\,\times\,}}{\mathtt{bc}}\right)}} = {\frac{{\mathtt{5}}}{{\mathtt{c}}}} = {\mathtt{5}}{\mathtt{\,\times\,}}{{\mathtt{c}}}^{-{\mathtt{1}}}$$

.

25b/5bc

=25*b/5*bc

=5*b*bc

=5b^2c