"Find all the complex roots of the following polynomials
A) $S(x)=135x^4 -324x^3 +234x^2 -68x+7$, knowing that all its real roots belong to the interval $(0.25;1.75)$
B)$M(x)=(x^3 -1+i)(5x^3 +27x^2 -28x+6)$ "
Well, in A) I don't know how to use the given information about real roots. I mean, I know that I can apply Bolzano but I don't think that's very useful. To find the complex roots I should have some information about a complex root in particular so that I could use Ruffini, but this is not the case.
And in B) I know that $(x^3 -1+i)$ is giving me some information related to a complex root, but that "^3" bothers me. If it wasn't there, I would know that $1-i$ is a root...