User:Nimdil

$$0 = \frac{2}{25} - \frac{9}{5}x + 2x^2$$

$$\Delta = (\frac{9}{5})^2 - 4 * 2 * \frac{2}{25}$$

$$\Delta = \frac{81}{25} - \frac{16}{25} = \frac{65}{25} = 2 \frac{15}{25}$$

$$x_1 = \frac{\frac{9}{5} - \frac{\sqrt{13}}{\sqrt{5}}}{4} = \frac{\frac{9 - \sqrt{65}}{5}}{4} = \frac{9 - \sqrt{65}}{20}$$

$$0=0,08 - 1,8x + 2x^2$$

$$\Delta = 1,8^2 - 4 * 2 * 0,08$$

$$\Delta = 3,24 - 0,64 = 2,6$$

$$\sqrt{\Delta} = 1,61245 $$

$$x_1 = \frac{1,8 - 1,61245}{4} = \frac {0,18755}{4} = 0,04689$$

$$c \land (a \lor b)$$