Réponse :
3.
a) -4x + 3
b) 3x - 7
c) -2x² + 3x - 5
d) x² + 3x - 1
4.
A) 8x + 3 - (6x + 2) = 8x + 3 - 6x - 2 = 2x + 1
B) (9x + 5) + (-2x + 3) = 9x + 5 - 2x + 3 = 7x + 8
C) (4x - 9) - (2x - 7) = 4x - 9 - 2x + 7 = 2x - 2
D) (9x + 5) -2x + 3 = 9x + 5 - 2x + 3 = 7x + 8
E) (4x - 9) - 2x + 7 = 4x - 9 - 2x + 7 = 2x - 2
H) 8x + 3 - 6x - 2 = 2x + 1
(A-H), (B-D), (C-E)
5.
K = 5x - (2x - 3) = 5x - 2x + 3 = 3x + 3 = 3 (x + 1)
L = 3x² - (4x² - x + 5) = 3x² - 4x² + x - 5 = -x² + x - 5
M = 4 + 6x - (-2x + 7) = 4 + 6x + 2x - 7 = 8x - 3
N = - 5x - (-5x² + x - 1) = -5x + 5x² - x + 1 = 5x² + 4x + 1
O = (6a + 8) - (4a + 2) = 6a + 8 - 4a - 2 = 2a + 6 = 2 ( a + 3)
P = (7b -2) + (3b - 5) = 7b - 2 + 3b - 5 = 10b - 7
Explications étape par étape
