By letting

we get derivatives


a) Substitute these into the differential equation. After a lot of simplification, the equation reduces to

Examine the lowest degree term
, which gives rise to the indicial equation,

with roots at r = 0 and r = 4/5.
b) The recurrence for the coefficients
is

so that with r = 4/5, the coefficients are governed by

c) Starting with
, we find


so that the first three terms of the solution are

A (-5, 6)
B (-5, 2)
C (-9, 2)
D (-9, 6)
As it is just a rotation around the origin by 180, you can just change the sign in front of the numbers :)
Yes. They both mean the same thing.