K= 5x - (2x - 3) - devant la () on change les signes dans la ()
K = 5x - 2x + 3
K = 3x + 3
L = 3.r - (4x2 - x + 5)
L = 3r - (8 - x + 5)
L = 3r - (13 - x)
L = 3r - 13 + x on met dans l'ordre r puis x puis chiffre
L = 3r + x - 13
M = 4 + 6x - (-2x + 7)
M = 4 + 6x + 2x - 7
M = 8x - 3
N= -5r - (-5r + - 1)
N = - 5r + 5r + 1 -5r +5r = 0 on les barre
N = 1
O = (60 + 8) - (4a + 2)
O = 68 - 4a - 2
O = - 4a + 66
P = (7b - 2) + (3b-5)
P = 7b - 2 + 3b - 5
P = 10b - 7
