Réponses

2014-10-20T17:43:46+02:00
1. 21x carré + 26x + 8 = 21x carré <=> 26x + 8 = 0 <=> 26x = -8 <=> x = -8/26 On simplifie la fraction : x = -4/13 :)
2014-10-20T17:50:28+02:00
2)
3x+2(7x+4)=0
15x+8=0
15x = -8
x =-8/15

3)
(3x+2)+(7x+4)=0
10x+6 =0
10x=-6
x= -6/10

4 )
(3x+2)(7x+4)=0
3x+2=0      7x+4=0
3x=-2         7x=-4
x=-2/3        x=-4/7

s={-2/3;-4/7}