Ex 2 et 3 svp..(en entier )

Exercice 3 :
A/
5(2x -4) < -5x +10         
10x - 20 + 5x <  10  
15x <  10 + 20 
15x <  30 
x <  30 / 15
x <  2


B/
(x - 3)² - (x - 1) (x - 3) = 0 
((x - 3) - (x - 1)) (x - 3) = 0 
(x - 3 - x + 1) (x - 3) = 0 
 -2 (x - 3) = 0 
(x - 3) = 0 
x = 3


G/
(3x + 5) (2x  - 1) + 9x² - 25 = 0
(3x + 5) (2x  - 1) + (3x)² - (5)² = 0
(3x + 5) (2x  - 1) + (3x + 5)(3x - 5) = 0
(3x + 5) ((2x  - 1) + (3x - 5)) = 0
(3x + 5) (5x - 6) = 0
(3x + 5) = 0    ou      (5x - 6) = 0
3x = -5           ou      5x = 6
x = -5/3          ou      x = 6/5