Question

x ao quadrado menos 18x + 45 = 0​

Answer 1

x² - 18x + 45 = 0

$\displaystyle \mathsf{ \Delta = {( -18)}^{2} - 4.(1).(45)} \\ \displaystyle \mathsf{ \Delta = 324 - 180} \\ \displaystyle \mathsf{ \Delta =144 }$

$\displaystyle \mathsf{x = \frac{18 \pm \: 12}{2}} \\ \displaystyle \mathsf{x = 15 \: ou \: x = 3}$