Question

x
${7x}^{2} - 14 = 0$

Answer 1

$7x^2-14=0 \\ \\ 7 x^{2} =14 \\ \\ x^{2} =14\div7 \\ \\ x^{2} =2 \\ \\ x=\pm \sqrt{2} \\ \\ S=\{- \sqrt{2} ,+ \sqrt{2} \}$