Question

x ao quadrado menos 49 igual a zero

Answer 1

x² - 49 = 0
x² = 49
x = \/49
x = +/-7

Answer 2

$x^{2} -49=0\to \\\\ x^{2} =49\to \\\\ x=\pm \sqrt{49} \to \\\\ x=\pm7\\\\\\ S=\{-7;7\}$