Bonjour,
6)
A = x - 3x² + 6x - 10 + 7x²
A = - 3x² + 7x² + x + 6x - 10
A = 4x² + 7x - 10
B = 9x - x² + 3 - 10x + 2x² - 5
B = - x² + 2x² + 9x - 10x + 3 - 5
B = x² - x - 2
C = 3 + x - 4x² + 5x² - x - 10
C = - 4x² + 5x² + x - x + 3 - 10
C = x² - 7
D = - x - 3x² + 5x - 8 + 6 + 2x
D = - 3x² - x + 5x + 2x - 8 + 6
D = - 3x² + 6x - 2.
7)
A = 2 + 6 (x + 8)
A = 2 + 6x + 48
A = 6x + 50
B = 2 (3x + 10) + 30
B = 6x + 20 + 30
B = 6x + 50
Donc : A = B.
