Resposta:

[tex] {2x}^{2} - 64 = 0 \\ {2x }^{2} = 64 \\ {x}^{2} = \frac{64}{2 } \\ {x}^{2} = 32 \\ x = + - \sqrt{32 } \\ x = + - \sqrt{4.8} \\ x = + - 2 \sqrt{8 } \\ x = + - 2 \sqrt{2.4} \\ x = + - 2.2 \sqrt{2 } \\ x = + - 4 \sqrt{2} [/tex]