Question

QUASE NINGUÉM SABE A RESPOSTA DESSA ATIVIDADE !!!!!!!!

Answer 1

Resposta:

a) x' = 3 + √2

x" = 3 - √2

b) x' = 4

x" = -7

c) x' = 6 + 4√2

x" = 6 - 4√2

d) x' = -4

x" = -4

e) x' =

x" =

f) x' = 5

x" = 0

g) x' = 5

x" = -5

h) x' = 5√2

x" = -5√2

Explicação passo-a-passo:

a) x² - 6x + 7 = 0

Δ = (-6)² - 4 . 1 . 7

Δ = 36 - 28

Δ = 8

x' = -(-6) + √8 / 2 . 1

x' = 6 + 2√2 / 2

x' = 3 + √2

x" = -(-6) - √8 / 2 . 1

x" = 6 - 2√2 / 2

x" = 3 - √2

b) x² + 3x - 28 = 0

Δ = (3)² - 4 . 1 . -28

Δ = 9 + 112

Δ = 121

x' = -(3) + √121 / 2 . 1

x' = -3 + 11 / 2

x' = 8/2

x' = 4

x" = -(3) - √121 / 2 . 1

x" = -3 - 11 / 2

x" = -14/2

x" = -7

c) 4x² - 12x + 7 = 0

Δ = (-12)² - 4 . 4 . 7

Δ = 144 - 112

Δ = 32

x' = -(-12) + √32 / 2 . 1

x' = 12 + 4√2 / 2

x' = 6 + 4√2

x" = -(-12) - √32 / 2. 1

x" = 12 - 4√2 / 2

x" = 6 - 4√2

d) x² + 8x + 16 = 0

Δ = (8)² - 4 . 1 . 16

Δ = 64 - 64

Δ = 0

x' = -(8) + √0 / 2 . 1

x' = -8/2

x' = -4  

x" -(8) - √0 / 2 . 1

x" = -8/2

x" = -4

 

e) 3x² - 2x + 1 = 0

Δ = (-2)² - 4 . 3 . 1

Δ = 4 - 12

Δ = 4 - 12

Δ = -8

f) x² - 5x = 0

Δ = (-5)² - 4 . 1 . 0

Δ= 25 - 0

Δ = 25

x' = -(-5) + √25 / 2 . 1

x' = 5 + 5 / 2

x' = 10/2

x' =  5

x" = -(-5) - √25 / 2 . 1

x' = 5 - 5 / 2

x' = 0/2

x' =  0

g) x² - 25 = 0

Δ = (0)² - 4 . 1 . -25

Δ = 0 + 100

Δ = 100

x' = -(0) + √100 / 2 . 1

x' =10/2

x' = 5

x" = -(0) - √100 / 2 . 1

x" = -10/2

x" = -5

h) 2x² - 100 = 0

Δ = (0)² - 4 . 2 . -100

Δ = 0 + 800

Δ = 800

x' = -(0) + √800 / 2 . 2

x' = 0 + 20√2 / 4

x' = 5√2

x" = -(0) - √800 / 2 . 2

x" = 0 - 20√2 / 4

x" = -5√2