Solve $\color{blue}{x^2-2x-1 = 0}$ using factoring.
First we need to factor trinomial $ \color{blue}{ x^2-2x-1 } $ and than we use factored form to solve an equation $ \color{blue}{ x^2-2x-1 = 0} $.
Since the quadratic trinomial cannot be factored out we solved the problem using quadratic formula.