Question

Me ajuda aqui é pra hoje

Answer 1

Resposta:

Explicação passo-a-passo:

a)  a=2; b=-8; c=8

b² - 4ac

(-8)² - 4.2.8

64 - 64

= 0

x = -b ± √Δ / 2a

x = -(-8) ±√0 / 2.2

x = 8 ± 0 / 4

x = 8 + 0 / 4 = 8/4 = 2

x = 8 - 0 / 4 = 8/4 = 2

S= {2}

B) a= 3; b= -7; c=2

b² - 4ac

(-7)² - 4.3.2

49 - 24 =

= 25

x = -b ± √Δ / 2a

x = -(-7) ± √25 / 2.3

x = 7 ± 5 / 6

x = 7 + 5 / 6 = 12/6 = 2

x = 7 - 5/ 6 = 2/6 = 1/3

S = { 2, 1/3}

c) m² + 9 - 4m = 0

a= 1; b= -4; c=9

b² - 4ac

(-4)² - 4.1.9

16 - 36 =

= - 20

S = {∅}  não há raiz

d) a=1; b=6; c=8

b² - 4ac

6² - 4.1.8

36 - 32 =

= 4

x = -b ± √Δ / 2a

x = -6 ± √4 / 2.1

x = -6 ± 2 / 2

x = -6 + 2 / 2 = -4/2 = -2

x = -6 - 2 / 2 = -8/2 = -4

S = {-2,-4}

e)  a= 1; b=2; c=-15

b² - 4ac

2² - 4.1.(-15)

4 + 60 =

= 64

x = -b ± √Δ / 2a

x = - 2 ± √64 / 2.1

x = -2 ± 8 / 2

x = -2 + 8 /2 = 6/2 = 3

x = -2 -8 / 2 = -10/2 = -5

S = {3, /5}

f) x² + 4x - 5 = 0

  a = 1; b=4; c=-5

b² - 4ac

4² - 4.1.(-5)

16 + 20 =

= 36

x = -b ± √Δ / 2a

x = -4 ± √36 / 2.1

x = -4 ± 6/ 2

x = -4 + 6 / 2 = 2/2 = 1

x = -4 - 6 / 2= -10/2 = -5

S = { 1, -5}