Answer:
[tex]x = - 2 + \sqrt{14} \: \: or \: \: x = - 2 - \sqrt{14} [/tex]
Step-by-step explanation:
[tex] {x}^{2} - 4x - 10 = 0 \\ {x}^{2} - 4x = 10 \\ {x}^{2} - 2(2x) = 10 \\ {x }^{2} - 2(2x) + 4 = 10 + 4 \\ {(x + 2)}^{2} = 14 \\ x + 2 = \sqrt{14} \: \: \: \: or \: \: \: x + 2 = - \sqrt{14} [/tex]
