Exercice 3 svp merci d'avance

Salut,

(2x-4)(9-3x) = 0

2x - 4 = 0 <=> 2x = 4 <=> x = 2
9 -3x  = 0 <=> -3x = -9 <=> x = 3

S = {2;3}

(3x+1)(1+3x) = 0

3x + 1 = 0 <=> 3x = -1 <=> x = -1/3
1 + 3x = 0 <=> 3x = -1 <=> x = -1/3

S = {-1/3}

7x(1-2x) = 0
7x = 0 <=> x = 0
1-2x = 0 <=> -2x = -1 <=> x = 1/2

S = {-1/2;0}

(5x-10)(8-4x) = 0
5x - 10 = 0 <=> 5x = 10 <=> x = 2
8 - 4x = 0 <=> - 4x = -8 <=> x = 2

S = {2}

Bonne soirée !

2x-4 =0                9-3x
2x = 4                    -3x = -9
x = 4/2                      x = -9/3
x = 2                          x = -3
solution (2, -3)

3x +1 =0                      1+3x =0
3x = -1                           3x = -1
x =  -1/3                           x = -1/3
donc une solution -1/3

7x =0                                    1-2x =0
x = 0/7                                     -2x = -1
x = 0                                            x = -1/-2 = 1/2

donc solution (0, 1/2)

5x-10 = 0                                         8-4x = 0
5x = 10                                            -4x = -8
x = 10/5                                              x =  -8/-4
x = 2                                                   x = 2

une seule solution 2