  It is well-known that one-dimensional time fractional diffusion-wave
equations with variable coefficients can be reduced to ordinary fractional
differential equations and systems of linear fractional differential equations
via scaling transformations. We then derive exact solutions to classes of
linear fractional differential equations and systems thereof expressed in terms
of Mittag-Leffler functions, generalized Wright functions and Fox H-functions.
These solutions are invariant solutions of diffusion-wave equations obtained
through certain transformations, which are briefly discussed. We show that the
solutions given in this work contain previously known results as particular
cases.
