Réponse exercice 1 :
1)
A = 3x - (7x-5) -6x + (2x+3)
A = 3x - 7+ 5 -6x + (2x+3)
A = 3x - 7+ 5 -6x + 2x + 3
A = -8x +8
A = -8( x - 1)
2)
B = 4x (6x - 3) - (2x +6) - 5x (-7x -8)
B = 24x² - 12x - 2x - 6 + 35x² + 40x
B = 59x² + 26x - 6
C = -5x (4x - 7) + 3x + (4x - 7) - 6x (9 -3x)
C = -20x² + 35x + 3x + 4x - 7 - 54x + 18x²
C = -2x² - 12x - 7
3)
C = -5x(-2) (4(-2) - 7) + 3(-2) + (4(-2) - 7) - 6(-2) (9 -3(-2))
C = -5(-2) * (-8-7) - 6 + (-8-7) - 6(-2) (9 +6)
C = -5(-2) * (-15) - 6 + (-15) - 6(-2) * 15
C = - 150 - 6 - 15 + 180
C = 9
Réponse exercice 2 :
I = [tex]-\frac{4}{-7} -\frac{2}{3} = \frac{12-14}{21} = \frac{2}{21} \\[/tex]
J = [tex]-\frac{21}{-14} - \frac{-15}{25} = \frac{3}{2} + \frac{3}{5} = \frac{15+6}{10} = \frac{21}{10}[/tex]
K = [tex]\frac{7}{-24} - \frac{-9}{10} = \frac{-35+108}{120} = \frac{73}{120}[/tex]
Voilà, j'espère que ça va t'aider !
