I think this is really weird.
I want to solve the following equation:
$$(2x^2+3x+5)^3+(2x^2+3x+5)^2=0$$
This is a polynomial equation of 6 degrees. It should have 6 roots.
But wolframalpha only returns 4 roots! Anything I miss?
This is the command I use:
solve ((2x^2+3x+5)^3)+((2x^2+3x+5)^2)=0
Edit: Ah, Wolframalpha doesn't return repeated roots. So now case solved.