Răspuns:
-2x²-3x-1=0
-X²-5x-6=0
-x +5x-6=0
-x²+2x-15=0
Explicație pas cu pas:
-2x²-3x-1=0
Δ = [tex]b^{2} - 4*a*c[/tex] = 9-8 = 1
[tex]x_{1} = \frac{-b + \sqrt{delta}}{2a}[/tex] = [tex]\frac{3+1}{-4}[/tex] = -1
[tex]x_{2} = \frac{-b - \sqrt{delta}}{2a}[/tex] = [tex]\frac{3-1}{-4}[/tex] = [tex]-\frac{1}{2}[/tex]
-X²-5x-6=0/(-1)* ⇒X²+5x+6=0
Δ = [tex]b^{2} - 4*a*c[/tex] = 25-24 = 1
[tex]x_{1} = \frac{-b + \sqrt{delta}}{2a}[/tex] = [tex]\frac{-5+1}{2}[/tex] = -2
[tex]x_{2} = \frac{-b - \sqrt{delta}}{2a}[/tex] = [tex]\frac{-5-1}{2}[/tex] = -3
-x +5x-6=0 ⇒4x-6=0 ⇒ 4x=6 ⇒ [tex]x=\frac{6}{4} =\frac{3}{2}[/tex]
-x²+2x-15=0/*(-1) ⇒x²-2x+15=0
Δ = [tex]b^{2} - 4*a*c[/tex] = 4-60 = -56 ⇒ Δ < 0 ⇒ [tex]x_{1} ; x_{2}[/tex] ∉ R
