Explications étape par étape :
Exercice 1: 1
Regroupement des termes "semblables"
A = x² + 3x² + 2x + 7x + 9x + 3 + 9
⇔ A = 4x² + 18x + 12
B = 4x² - 9x² + 2x - 7x + 9x - 13 - 1
⇔ B = -5x² + 4x - 14
C = 2x³ + 5x² – 3x + 2x² - 7x³ – 15x + 9 - 19 - 8x²
⇔ C = -5x³ - x² - 18x - 10
D = -15 + 8x² - 12x + 15x - x² – 25
⇔ D = 7x² + 3x - 40
2. E = 7(4x - 3)
⇔ E = 28x - 21
F = 2x(x² + 4x)
⇔ F = 2x³ + 8x²
G = 3(x - 5) - 4(x + 2)
⇔ G = 3x - 15 - 4x - 8
⇔ G =-x - 23
H = -8(-x - 2) + 6x(x – 9)
⇔ H = 8x + 16 + 6x² - 54x
⇔ H = 6x² - 46x + 16
3. I = 6y – yz
⇔ I = y ( 6 - z )
J = x² + 6xy
⇔ J = x ( x + 6y )
K = 45xyz - 30xy + 15xz
⇔ K = 15x ( 3yz - 2y + z )
L = (3 – 2x) (5 - x) + (3 - 2x) (7 - 4x)
⇔ L = ( 3 - 2x ) ( 5 - x + 7 - 4x )
⇔ L= ( - 2x + 3 ) ( -5x + 12 )
