PetiteKyojo Bonjour,

Exercice 7 : 

1)x²-x-6 = juste

2x²+3x-2
2x²+4x-x-2
2x×(x+2)-(x+2)
=(2x-1)×(x+2)

2)2/x²-x-6+x/2x²+3x-2=0
2/x²-x-6+x/2x²+3x-2=0,x≠3,x≠-2,x≠1/2
2/x²+2x-3x-6+x/2x²+4x-x-2=0
2/x×(x+2)-3(x+2)+x/2x×(x+2)-(x+2)=0
2/(x-3)×(x+2)+x/(2x-1)×(x+2)=0
2(2x-1)+x×(x-3)/(x-3)×(2x-1)×(x+2)=0
4x-2+x²-3x/(x-3)×(2x-1)×(x+2)=0
x-2+x²/(x-3)×(2x-1)×(x+2)=0
x²+x-2/(x-3)×(2x-1)×(x+2)=0
x²+2x-x-2/(x-3)×(2x-1)×(x+2)=0
x×(x+2)-(x+2)/(x-3)×(2x-1)×(x+2)=0
(x-1)×(x+2)/(x-3)×(2x-1)×(x+2)=0
x-1/(x-3)×2x-1)=0
x-1=0
x=1,x≠3,x≠-2,x≠1/2
x=1