Question

Determine as raízes reais da equação do 2 ° grau.

Answer 1

6 x² + x = 0
x(6 x  + 1 ) = 0
x = 0
6 x + 1 = 0
6 x =  -1
x = -1/6
S = {0 ; -1/6}
B)X² + 5 X  - 6 = 0
Δ = b² - 4.a.c
Δ = 5² - 4.1.-6
Δ = 25 + 24
Δ = 49  ⇒ √ 49 = 7
x = - b + ou - 7/2
x´= -5 + 7/2
x´= 2/2 ⇒1
x´´ = -5 -7/2
x´´ = -12/2 ⇒ -6
S = {-6  ; 1 }

C)x²  - x  -20 = 0
Δ = b² - 4.a.c
Δ = (-1)² - 4. 1 - 20
Δ = 1 + 80
Δ = √81 ⇒9
x = - b + ou - 9/2
x´= -(-1) + 9/2
x´= 1 + 9 /2
x´= 10/2⇒5
x´´ = 1 - 9/2
x´´ = -8/2 ⇒ -4
S = -4 ; 5}