Question

Resolve essa conta de segundo grau x²-x-12=0

Answer 1

x² - x - 12 = 0

a = 1
b = - 1
c = - 12

Δ = b² - 4.a.c
Δ = ( - 1)² - 4 . 1 . ( - 12)
Δ = 1 + 48
Δ = 49

x = - b + - √Δ/ 2a
x = - ( - 1) + - √49/ 2.1
x = 1 + - 7/2

x' = 1 + 7/2  ⇒ x' = 8/2 ⇒ x' = 4
x" = 1 - 7/2 ⇒ x" = - 6/2 ⇒ x" = - 3

S = { - 3 e 4 }

Answer 2

a= 1
b=-1
c= -12
Δ=b²-4·a·c
Δ=(-1)²-4·1·(-12)
Δ=1+48
Δ=49

x=-b+-√Δ÷2·a
x=1+-√49÷2
x1= 1+√49÷2------>4
x2= 1-√49÷2--------> -3