Bonsoir, je n’arrive pas du tout à faire ces exercices :( pourriez vous m’aidez please ? Merci d’avance.

Réponse:

Exercice 2 :

a) -2x +5 -4x +3

= -2x -4x +5 +3

= -6x + 8

b) -5x +4x +3

= -x +3

c) x² +x +3x +5x² +1

= x² +5x² +x +3x +1

= 6x² +4x +1

d) 6x² -3 +5x -7x² +4 -2x

= 6x² -7x² +5x -2x -3 +4

= -x² +3x +1

e) -2x × 3x +2x +3x² -4x

= -6x² +3x² +2x -4x

= -3x² -2x

f) 2×(3x²) - (4x)×x +x²

= 6x² - 4x² + x²

= 2x² +x²

= 3x²

Exercice 3 :

a) 3x +5x × (-2x) + x×2

= 3x -10x² + 2x

= 3x +2x -10x²

= 5x -10x²

b) 2+ 3×4 -x -x

= 2+ 12 -2x

= 14 -2x

c) (-x) × (-x) + (-x)×x

= x² + -x²

= x² -x²

= 0

d) -3×2 + (x×5) × 3 + x×2x

= -6 + 5x ×3 + 2x²

= -6 + 15x + 2x²