Question

Resolva a equação:
a)x² + x + 2 = 0

b)- x² - x + 12 = 0

c)- x² + 2x + 8 = 0

Answer 1

Resposta:

A)

delta= 1² - 4.1.(-2)

delta= 1+8

delta=9

x= (-(-1) + ou - 3)/2.1

x'= 1 + 3 = 4/2 = 2

x''= 1 - 3 = -2/2 = -1

b)X² - X - 12 = 0

Δ = b² - 4.a.c

Δ = (-1)² - 4.1.(-12)

Δ = 1 + 48

Δ = 49

X = -b +/- √Δ /2              

X = 1 +/- √49 /2

X = 1 +/- 7 /2            

 

X¹ = 1 + 7 /2

X¹ = 8/2

X¹ = 4

X² = 1 - 7 /2

X² = - 6/2

X² = - 3

c) x² + 2x - 8 = 0

Δ = 2² - 4.1.(-8)

Δ = 4 + 32

Δ = 36

 

x = -4 e x = 2.