Question

resolva as equaçoes completas e incompletas do segundo grau:
$2x^{2} -8= 0$
$2x^{2} -2=0$
$5x^{2} =0$
$x^{2} -5x+6=0$

Answer 1

a)

2x² - 8 = 0 (÷2)

x² - 4 = 0

x² = 4 (√)

√x² = √4

x = ±2

b)

2x² - 2 = 0 (÷2)

x² - 1 = 0

x² = 1 (√)

√x² = √1

x = ± 1

c)

5x² = 0

x² = 0/5

x² = 0 (√)

x = ± 0

x = 0

d)

x² - 5x + 6 = 0

a = 1

b = -5

c = 6

∆ = b² - 4ac

∆ = 25 - 24

∆ = 1

x = -b ± √∆/2a

x = 5 ± 1/2

x1 = 5 + 1/2 = 6/2 = 3

x2 = 5 - 1/2 = 4/2 = 2