bjr
ex 3
G = 3x² - 5x = 3x*x - 5x = x (3x-5)
H = (4a+1) (3a-2) - (4a+1) (a+1)
= (4a+1) (2a-2-(a+1))
= (4a+1) (2a - 2 -a - 1)
= (4a+1) (a-3)
I = 9x² - 16 = (3x)² - 4² = (3x+4) (3x-4)
ex 4
8x + 3 = - 7
8x = -7-3
x = -10/8 = -1,25
3x + (2x+1)/3 = x/6 + 1/2
je mets tous sous le même dénominateur :
18x/6 + [2 (2x+1)] / 6 = x/6 + 3/6
18 + 2 (2x+1) = x + 3
18 + 4x + 2 = x + 3
3x = -17
x = -17/3
pour le 1 - reprends ton cours.
