Question

deternine os seguintes conjuntos enumerando os seus elementos.

a={x e r /x²-5x+6=0}
b={x e R/2x²-8x+8=0}
c={x e r/x²+5x+4=0}

plsssssss
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Answer 1

A = {x ∈ ℝ | x² - 5x + 6 = 0}

A = {x ∈ ℝ | 2 e 3}

x² - 5x + 6 = 0

a = 1, b = - 5, c = 6

x = (- b ± √(b² - 4ac))/2a

x = (- (- 5) ± √((- 5)² - 4 . 1 . 6))/(2 . 1)

x = (5 ± √(25 - 21))/2

x = (5 ± √1)/2

x = (5 ± 1)/2

x = (5 + 1)/2 = 6/2 = 3

x = (5 - 1)/2 = 4/2 = 2

B = {x ∈ ℝ | 2x² - 8x + 8 = 0}

B = {x ∈ ℝ | 2}

2x² - 8x + 8 = 0

x² - 4x + 4 = 0

a = 1, b = - 4, c = 4

x = (- b ± √(b² - 4ac))/2a

x = (- (- 4) ± √((- 4)² - 4 . 1 . 4))/(2 . 1)

x = (4 ± √(16 - 16))/2

x = (4 ± √0)/2

x = (4 ± 0)/2

x = 4/2

x = 2

C = {x ∈ ℝ | x² + 5x + 4 = 0}

C = {x ∈ ℝ | - 4 e - 1}

x² + 5x + 4 = 0

a = 1, b = 5, c = 4

x = (- b ± √(b² - 4ac))/2a

x = (- 5 ± √(5² - 4 . 1 . 4))/(2 . 1)

x = (- 5 ± √(25 - 16))/2

x = (- 5 ± √9)/2

x = (- 5 ± 3)/2

x = (- 5 + 3)/2 = (- 2)/2 = - 1

x = (- 5 - 3)/2 = (- 8)/2 = - 4

att. yrz