Question

Resolva as equações incompletas abaixo usando números reais.

-2x² + 64 = 0

Answer 1

-2x² + 64 = 0 
-2x² = - 64
 2x² = 64
   x² = 64/2
   x² = 32
   x = √32
            ________
   x = √ 2² . 2² . 2
========================
   x = (+ - ) 4 √2
Solução:
x = - 4√2 ou x  = 4√2

Answer 2

$-2 x^{2} +64=0\to \\\\ -2x^2=-64~(-1)\to \\\\ 2x^2=64\to \\\\ x^2= \dfrac{64}{2} \to \\\\ x^2=32\to \\\\ x=\pm ~\sqrt{32} \to \\\\ x=\pm ~\sqrt{2^2.2^2.2} \to \\\\ x=\pm~2.2 \sqrt{2} \to \\\\ x=\pm~4 \sqrt{2} \\\\\\ \boxed{S=\{-4 \sqrt{2}~;~4 \sqrt{2} }$