Odpowiedź:
Ćwiczenie 5
c)
3x² - 5x - 2 = 0
a = 3 , b = - 5 , c = - 2
Δ = b² - 4ac = (- 5)² - 4 * 3 * (- 2) = 25 + 24 = 49
√Δ = √49 = 7
x₁ = (- b - √Δ)/2a = ( 5 - 7)/6 = - 2/6 = - 1/3
x₂ = (- b + √Δ)/2a = (5 + 7)/6 = 12/6 = 2
Ćwiczenie 1
c)
4x² - 28x + 49 = 0
a = 4 , b = - 28 , c = 49
Δ = b² - 4ac = (- 28)² - 4 * 4 * 49 = 784 - 784 = 0
x₁ = x₂ = - b/2a = 28/8 = 7/2 = 3 1/2 = 3,5
