Question

resolva as equações de 2grau

c) x² + 2x – 8 = 0
d) 2x² - 8x + 8 = 0

Answer 1

c) ∆= 2² - 4.1.(-8)

∆= 4 + 32

∆= 36

x= - 2 ±√36/2.1

x= -2 ±6/2

x1= -2+6/2= 4/2=2

x2= -2-6/2= -8/2= -4

S= { 2, -4}

d) ∆= (-8)² -4.2.8

∆= 64 - 64

∆= 0

x= - (-8)/2.2

x= +8/4

x= 2

S= { 2}