bjr
1 on effectue les multiplications possibles et 2 on regroupe les termes
A = 3 + 14x - 4x (2x*7 = 14x)
A = 3 + 10x
B = 3x² + 4 + 2x - 5x² - 9 + 15x
B = 3x² - 5x² + 2x + 15x + 4 - 9
B = -2x² + 17x - 5
Ex 1
additionner
4x + 5x = 9x
7x - 5x = 2x
4x+ 3x = 7x
-4x + 5x = x
6x + 7x = 13
tu ax compris..