Réponse:
Exercice 1 :
A= [8×5 -(4+3×2)]÷ (12×2-9)
A= [8×5 -(4+6)] ÷ (24-9)
A= [8×5 -10] ÷ 15
A= [40 -10] ÷15
A= 30 ÷15
A= 2
Exercice 3 :
D= -3(x+7) + (-4+2x) + 5x(6-7x) - (2-5x)
D= -3×x - 3×7 -4 +2x + 5x×6 - 5x×7x -2 +5x
D= -3x -21 -4 +2x + 30x - 35x² -2 +5x
D= -35x² -3x +2x +30x +5x -21 -4 -2
D= -35x² -3x +37x -27
D= -35x² +34x -27
