All all zeros for the following function f(x)= x5- 10x4 + 23x3 +56x2 -290x + 300

x = -2, 3 and 5 are the real roots.

There are also complex roots x = 3 + i and 3 - i.

I'm lazy. I used
http://xrjunque.nom.es/precis/rootfinder.aspx