Bonjour,
6x²-7x-3
Calculer:
k(0)= 6(0)²-7(0)-3= -3
k(-1)= 6(-1)²-7(-1)-3= 6+7-3= 10
k(3/2)= 6(3/2)²-7(3/4)-3= 6(9/4)-21/3-3= 54/4-21/3-3= (54x3-21x4-3x12)/ 12= 42/12= 7/2
k(-1/3)= 6(-1/3)²-7(-1/3)-3= 6/9+7/3-3= (6+7x3-3x9)/9= 0
Résoudre 6x²-7x-3=0
On factorise et on obtient :
(2x-3)(3x+1)= 0
2x-3= 0 ou 3x+1= 0
x= 3/2 x= -1/3
S= { -1/3 ; 3/2 }
