Question

a) 2x2 - 6x +8=0
b) x2 - 8x + 14 = 0
c) x2 - 6x - 3=0
d) 3x2 + 2x + 1 = 0​

Answer 1

Resposta:

Explicação passo-a-passo:

a) 2x² - 6x +8=0

Δ = b² - 4.a.c

Δ = (-6)² - 4 × 2 × 8

Δ = 36 - 32

Δ = 4

x = -b ± √Δ / 2.a

x = - (-6) ± √4 / 2 × 2  

x = 6 ± 2 / 4

x' = 6 + 2 / 4

x' = 8 / 4 = 2

x" = 6 - 2 / 4  

x" = 4 / 4 = 1

b) x² - 8x + 14 = 0

Δ = b² - 4.a.c

Δ = (-8)² - 4 × 1 × 14

Δ = 64 - 56

Δ = 8

x = -b ± √Δ / 2.a

x = - (-8) ± √8 / 2 × 1

x = 8 ± √8/ 2

x' = 8 + √8 / 2

x" =  8 - √8 / 2

c) x² - 6x - 3= 0

Δ = b² - 4.a.c

Δ = (-6)² - 4 × 2 × (-3)

Δ = 36 - 24

Δ = 12

x = -b ± √Δ / 2.a

x = - ( -6 ) ± √12 / 2 × 1  

x = 6 ± √12 / 2  

x' = 6 + √12 / 2  

x" = 6 - √12 / 2

d) 3x² + 2x + 1 = 0​

Δ = b² - 4.a.c

Δ = 2² - 4 × 3 × 1

Δ = 4 - 12

Δ = -8