Daar was ie weer...:-)
\(\eqalign{
& 4{x^2} - 4x - 3 = 0 \cr
& a \cdot b = - 12 \cr
& a + b = - 4 \cr
& a = - 6\,\,en\,\,b = 2 \cr
& 4{x^2} - 6x + 2x - 3 = 0 \cr
& 2x(2x - 3) + 2x - 3 = 0 \cr
& (2x + 1)(2x - 3) = 0 \cr
& 2x + 1 = 0 \vee 2x - 3 = 0 \cr
& 2x = - 1 \vee 2x = 3 \cr
& x = - \frac{1}{2} \vee x = 1\frac{1}{2} \cr}\)
...ik ken nog meer kunstjes, maar dit is wel mijn favoriet...:-)