  In in this paper we show how using D.A. it is found a simple change of
variables (c.v.) that brings us to obtain differential equations simpler than
the original one. In a pedagogical way (at least we try to do that) and in
order to make see that each c.v. corresponds to an invariant solution (induced
by a symmetry) or a particular solution, we compare (with all the tedious
details, i.e. calculations) the proposed method with the Lie method. The method
is checked even in ODEs that do not admit symmetries.
