Question

calcule as raízes da equação 5x2-20=0

Answer 1

$5 x^{2} -20=0 \\ 5 x^{2} =20 \\ x^{2} =20/5 \\ x^{2} =4 \\ x=+- \sqrt{4} \\ x=+-2 \\x=2 \\ x=-2 \\ x= [-2,2]$

Answer 2

5x² - 20 = 0

5x² = 20
x² = 20 / 5
x² = 4
x = ± √4

x' = -2

x'' = 2

S= {-2, 2}