Bonjour URGENT 19pts LES( / )SONT DES FRACTIONS LES (x) SONT DES LETTRES A=2x-1/2-4x-5/8=0 B= 3x-5/x-2=3/2 C= 8xcarré-2x(4x-2)=3x-2 D=4x-2/4-7x-2/6=3/2 E= 2x-1/

A) 2x - 1/2 - 4x - 5/8 = 0
-2x = 4/8 + 5/8
-2x = 9/8
x = -9/16

B) 3x - 5/x - 2 = 3/2
3x^2 - 5 - 2x = 3x/2
6x^2 - 10 - 4x = 3x
6x^2 - 7x - 10 = 0

Delta = (-7)^2 - 4 * 6 * (-10)
Delta = 49 + 240
Delta = 289
V(delta) = 17 > 0

Donc deux solutions :
X1 = (7 - V(delta)) / 2 = (7-17)/2 = -10/2 = (-5)
X2 = (7 + V(delta)) / 2 = (7+17)/2 = 24/2 = 12

C) 8x^2 - 2x(4x - 2) = 3x - 2
8x^2 - 8x^2 + 4x = 3x - 2
4x - 3x = -2
x = -2

D) 4x - 2/4 - 7x - 2/6 = 3/2
-3x - 1/2 - 2/6 = 3/2
-3x = 9/6 + 2/6 + 3/6
-3x = 14/6
-3x = 7/3
x = - 7/9

E) 2x - 1/4 = 4x - 2/2
-1/4 + 4/4 = 4x - 2x
3/4 = 2x
x = 3/8

F) (3x - 1)(2x - 3) - 6x^2 + 350 = 0 ?!?!
6x^2 - 9x - 2x + 3 - 6x^2 + 350 = 0
-11x + 347 = 0
11x = 347
x = 347/11

G) -(3x - 4) + 4(2x - 1) = 3x
-3x + 4 + 8x - 4 = 3x
5x - 3x = 0
2x = 0
x = 0

H) 4(7x - 2) - 2(x - 2) = 0
28x - 8 - 2x + 4 = 0
26x = 4
x = 4/26
x = 2/13

I) x - 1/2 - x + 4/12 = 3/2
-6/12 + 4/12 = 18/12
-2/12 = 18/12
Impossible ! Il n'y a pas une erreur dans l'énoncé ?