Aus Online Mathematik Brückenkurs 1

The equation \displaystyle (x-3)(x-\sqrt{3}\,)=0 is a second-degree equation which has \displaystyle x=3 and \displaystyle x=\sqrt{3} as roots; when \displaystyle x=3, the first factor is zero and when \displaystyle x=\sqrt{3} the second factor is zero.

If we expand the equation's left-hand side, we get the equation in standard form,

\displaystyle \begin{align} (x-3)(x-\sqrt{3}\,) &= x^{2}-\sqrt{3}x-3x+3\sqrt{3}\\[5pt] &= x^{2}-(3+\sqrt{3}\,)x+3\sqrt{3}=0\,\textrm{.} \end{align}

Note: the general answer is

\displaystyle ax^{2}-(3+\sqrt{3}\,)ax+3\sqrt{3}a=0\,,

where \displaystyle a\ne 0 is a constant.