\[- \frac{1}{4}x^{2} + 2x - 30 = 0\ \ \ | \cdot ( - 4)\]
\[x² - 8x + 12 = 0\]
\[x_{1} + x_{2} = 8;\ \ x_{1} \cdot x_{2} = 12\]
\[x_{1} = 6,\ \ x_{2} = 2.\]
\[- \frac{1}{4}x^{2} + 2x - 3 =\]
\[= - \frac{1}{4} \cdot (x - 6)(x - 2).\]