I'm following up from this question:
I have had trouble with this question:
"Solve the equation $8x^3−38x^2+57x−27=0$" if the roots are in geometric progression.
Any help would be appreciated.
I eventually solved the equation (please check @lab bhattacharjee's answer), but I got two answers for $r$, which were 3/2 and 2/3. How exactly do I know which is correct? I've been stuck for ages, so I'd prefer a full explanation rather than hints.
Any help would be appreciated. Thanks.