Solve the equation x^3 + 9x + 4 = 0 by Cardon's method?

It is called Cardano's method. Spelling mistakes in math are almost always fatal. Google.com has lot's of links to explanations, and wikipedia.org has a paragraph under "cubic equation". It apparently is not as simple as the quadratic formula. I have never used it or even heard of it.
www.google.com/#q=Cardano's+method