Question

x² - 49 = 0 e 2x² - 18x = 0

Answer 1

x² - 49 = 0

x² = 49

x = ± √49

x = ± 7

x' = 7

x'' = - 7

2x² - 18x = 0

x² - 9x = 0

x (x - 9) = 0

x' = 0

x'' - 9 = 0 ⇒ x'' = 9