Respostas

2014-05-31T20:40:54-03:00
Olá, Janacdsanjo!

a) x² + 7x + 10 = 0
a = 1
b = 7
c = 10
Δ = b² - 4ac
Δ = 7² - 4.1.10
Δ = 49 - 40
Δ = 9

-b +- raiz de delta / 2.a
-7 +- raiz de 9/2.1
-7 +-3/2

x' = -7+3/2 = -4/2 = -2
x'' = -7-3/2 = -10/2 = -5

b) 2x² - 3x + 4 = 0
a = 2
b = -3
c = 4
Δ = b² - 4ac
Δ = (-3)² - 4.2.4
Δ = 9 - 32
Δ = -23

c) x² + 2x + 1 = 0
a = 1
b = 2
c = 1
Δ = b² - 4ac
Δ = 2² - 4.1.1
Δ = 4 - 4
Δ = 0

-b / 2a
-2 / 2.1
-2/2
= -1
1 5 1