Question

Determine as raizes de cada equaçao a seguir
A) x²-12x-13=0
b) 2x²+x1=0
c)x²+5x+6=0

Answer 1

Δ = b²-4*a*c  Δ =(-12x)²-4*1²*(-13)  Δ =144-4*(-13)  Δ =144+52  Δ =196
 Δ =√196   Δ =14

Answer 2

Explicação passo-a-passo:

a) x² - 12x - 13 = 0

Δ = (-12)² - 4.1.(-13)

Δ = 144 + 52

Δ = 196

x = (12 ± √196)/2.1 = (12 ± 14)/2

• x' = (12 + 14)/2 = 26/2 = 13

• x" = (12 - 14)/2 = -2/2 = -1

b) 2x² + x - 1 = 0

Δ = 1² - 4.2.(-1)

Δ = 1 + 8

Δ = 9

x = (-1 ± √9)/2.2 = (-1 ± 3)/4

• x' = (-1 + 3)/4 = 2/4 = 1/2

• x" = (-1 - 3)/4 = -4/4 = -1

c) x² + 5x + 6 = 0

Δ = 5² - 4.1.6

Δ = 25 - 24

Δ = 1

x = (-5 ± √1)/2.1 = (-5 ± 1)/2

• x' = (-5 + 1)/2 = -4/2 = -2

• x" = (-5 - 1)/2 = -6/2 = -3