Question

8) Calcule as raízes da equação:
a) (2x + 3)2 - 9 = 12x
b) 7x2 - 21 = 0
c) x2 + 5x + 2 =
d) x2 - 6x + 9 =​

Answer 1

Resposta:

a)x=-3/6

b)x=√3

c)x1=-0,877/2

  x2=-9,123/2

d)x1=x2= 3

Explicação passo-a-passo:

a) (2x + 3)2 - 9 = 12x

6x+6-9=12x

-3=6x

x=-3/6

b) 7x²- 21 = 0

7x²= 21

x²= 21/7

x=√3

c) x² + 5x + 2

Δ=5²-4.1.2

Δ=25-8

Δ=17

-5±√17/2.1

x1=-5+4,123/2 > -0,877/2

x2=-5-4,123/2 > -9,123/2

d)x² - 6x + 9

Δ=(-6)²-4.1.9

Δ=36-36

Δ=0

-(-6)±√0/2.1

x1=x2=6/2 > 3