Question

rezolvati in R : |X|^2-4X+3=0​

Answer 1

Răspuns:

Explicație pas cu pas:

x² - 4x + 3 = 0

a = 1

b = - 4

c = 3

Δ = b² - 4ac = (-4)² - 4×1×3 = 16 - 12 = 4

x₁ = ( - b +√Δ)/2a = (4 + 2)/ 2 = 6/2 = 3

x₂ = (- b - √Δ)/2a = (4 - 2)/2 = 2/2 = 1

S = {1; 3}

II metoda :

x² - 4x + 3 = 0  

x² - x - 3x + 3 = 0

x(x - 1) - 3(x - 1) = 0

(x - 1)(x - 3) = 0

x - 1 = 0   = > x = 1

x - 3 = 0  = > x = 3

S = {1; 3}

Answer 2

|x|²-4x+3=0

x²-4x+3 = 0

x²-x-3x+3 = 0

x(x-1)-3(x-1) = 0

(x-1)(x-3) = 0

=> x-1 = 0 sau x-3 = 0 => x = 1 sau x = 3

=> x ∈ {1; 3}