Réponses

2014-05-17T17:35:00+02:00
Salut :)

23)

(4x-8)(3x-1)=0
4 (3x²-7 x+2) = 0
12 x²-28 x+8 = 0
alors 
x = 1/3  ou  x = 2

(-5x+10)(7x-3)=0
-5 (x-2) (7 x-3) = 0
-35 x²+85 x-30 = 0
alors
x = 3/7 ou  x=2

25)

(1/2x+1)(2/3x+4)=0
1/3 (x+2) (x+6) = 0
x²/3+(8 x)/3+4 = 0
alors 
x= -6  ou x= -2

(5/3x-7)(5/3x+6)=0
1/9 (5 x-21) (5 x+18) = 0
(25 x²)/9-(5 x)/3-42 = 0
alors
x = -18/5 ou  x = 21/5

bonne journee