Question

Resolva as equações utilizando a fórmula de bháskara:
1) x² + 2x - 8 = 0 2) x² - 5x + 6 = 0 3) x² - 4x - 5 = 0 8) 2x² - 7x - 15 = 0

Answer 1

Resposta:

1) x² + 2x - 8 = 0

Δ = b² - 4ac

Δ = 2² - 4*1*(-8)

Δ = 36

x = -b ± √Δ / 2a

x₁ = 7/2 e  x₂ = -11/2

S = {7/2; -11/2}

2) x² - 5x + 6 = 0

Δ = b² - 4ac

Δ = (-5)² - 4*1*6

Δ = 1

x = -b ± √Δ / 2a

x₁ = 3 e  x₂ = 2

S = {2, 3}

3) x² - 4x - 5 = 0

Δ = b² - 4ac

Δ = (-4)² - 4*1*(-5)

Δ = 36

x = -b ± √Δ / 2a

x₁ = 7/2 e  x₂ = -11/2

S = {7/2; -11/2}

8) 2x² - 7x - 15 = 0

Δ = b² - 4ac

Δ = (-7)² - 4*2*(-15)

Δ = 169

x = -b ± √Δ / 2a

x₁ = 5 e  x₂ = -3/2

S = {-3/2; 5}

Espero que eu tenha ajudado!!!