Question

Resolva a equaçao -2x²+800=0

Answer 1

800= -2x^2
400=x^2
x=√400
x=20

Answer 2

$-2x^2+800 = 0\\\\ -2x^2 = -800\\\\ 2x^2 = 800\\\\ x^2=\frac{800}{2}\\\\ x^2 = 400\\\\ \boxed{x=+\ ou\ -\ 20}$