Exercice Maths 11 POINTS A) 5(2x - 4) < -5x + 10 B) (x - 3) au carré - (x - 1) (x - 3) = 0 C) (3x + 5) (2x - 1) + 9xau carre -25=0

A) 5(2x - 4) < -5x + 10
10x-20<10-5x
15x<30
x<2

B) (x - 3) au carré - (x - 1) (x - 3) = 0
(x-3)(x-3-x+1)=0
(x-3)(-2)=0
x=3

C) (3x + 5) (2x - 1) + 9xau carre -25=0
(3x+5)(2x-1+3x-5)=0
(3x+5)(5x-6)=0
3x+5=0 ou 5x-6=0
x=-5/3 ou x=6/5

5(2x - 4) < - 5x + 10
10x - 20 < - 5x + 10
10x + 5x < 10 + 20
15x < 30
x < 30/15
x < 2

(x - 3)² - (x - 1)(x - 3) = .
(x - 3)(x - 3 - x + 1) = 0
(x - 3) * (- 2) = 0
x - 3 = 0
x = 3

(3x + 5)(2x - 1) + 9x² - 25 = 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