Réponse :
Explications étape par étape
Bonsoir
4x^2 + 2x - 5 =0
[tex]\Delta = 2^{2} - 4 * 4 * (-5) = 4 + 80 = 84[/tex]
[tex]\sqrt{\Delta} = 2\sqrt{21}[/tex]
X1 = (-2 + 2V21)/(2 * 4) = -1/4 + (V21)/2
X2 = (-2 - 2V21)/8 = -1/4 - (V21)/2
3x² +6x +3 =0
3(x^2 + 2x + 1) = 0
3(x + 1)^2 = 0
x + 1 = 0
x = -1
-5x² + 5x -3 =0
[tex]\Delta = 5^{2} - 4 * (-5) * (-3) = 25 - 60 = -40 < 0[/tex]
Pas de solution
4x² + 7x - 2 =0
[tex]\Delta = 7^{2} - 4 * 4 * (-2) = 49 + 32 = 81[/tex]
[tex]\sqrt{\Delta} = 9[/tex]
X1 = (-7 - 9)/(2 * 4) = -16/8 = -2
X2 = (-7 + 9)/8 = 2/8 = 1/4
