Răspuns:
x₁ = -5 ; x₂ = -1
Explicație pas cu pas:
x²+6x+5 = 0 <=> x²+5x+x+5 = 0 <=>
Varianta 1:
x(x+5) + (x+5) = 0 <=> (x+5)·(x+1) = 0 => x₁ = -5 ; x₂ = -1
Varianta 2:
x²+6x+5 = 0
a = 1 ; b = 6 ; c = 5
Δ = b²-4ac = 6²-4·1·5 = 36-20 = 16
√Δ = √16 = 4
x₁,₂ = (-b±√Δ)/2a = (-6±4)/2
x₁ = (-6-4)/2 = -10/2 => x₁ = -5
x₂ = (-6+4)/2 = -2/2 => x₂ = -1
