Răspuns:
Explicație pas cu pas:
-x²-x+2 = 0
a = -1 ; b = -1 ; c = 2
Δ = b²-4ac = (-1)²-4·(-1)·2 = 1+8 = 9 => √Δ = √9 = 3
x₁,₂ = (-b±√Δ)/2a = (1±3)/(-2)
x₁ = (1+3)/(-2) = 4/(-2) => x₁ = -2
x₂ = (1-3)/(-2) = (-2)/(-2) = > x₂ = 1
6x²-x-1 = 0
a = 6 ; b = -1 ; c = -1
Δ = (-1)²-4·6·(-1) = 1+24 = 25 => √Δ = √25 = 5
x₁,₂ = (1±5)/12
x₁ = (1-5)/12 = -4/12 => x₁ = -1/3
x₂ = (1+5)/12 = 6/12 => x₂ = 1/2
