réduire chaque expression : exercice 1, 4 et 6 svp

Exercice 1:

a) 2x + 3x = 5x
b) 14x -4x = 10x
c) 2x -7x = -5x
d) 14x - 14x = 0
e) y + 7y = 8y
f) y - 9y = -8y

Exercice 2 :

a) 4x +5x +2x = 11x
b) -5x² -9x² -3x² = 17x²
c) -4a +2a -7a = 9a
d) 15y -11y -y = 3y
e) 15b² +7b² -3b² = 19b²
f) a² -3a² -15a² = -17a²

Exercice 3 :

A = x - 6 - 5x² -30 - x
= - 5x² -36

Pour x = 1 on a : -5(1)² - 36 = - 5 - 36 = -41


B = 9x² - x - 6 +x² -13 -8x +7 -3x²
= 7x² - 9x -12

Pour x = 1 on a : 7(1)² - 9(1) -12 = 7 - 9 - 12 = -14


C = 12x - x² -10 + x -3 -8x² +1 -2x
= -9x² + 11x -12

Pour x = 1 on a : -9(1)² + 11(1) -12 = -9 + 11 - 12 = - 10