A= 5-10+9 = -5+9 = 4
B = -4 x (2-12) = -4 x (-10) = 40
C = 12 - (7 x(15-8)) = 12 -(7 x 7) =
12-49 = - 37
D = 3 + 21 / (9-12) = 3 + 21/(-3) = 3 - 7 = -4
2.
A = 3a^2 - 5a + 14
B = 20a^2 -25a + 12a -15 = 20a^2 -13a -15
3.
Magasin1 : (300 + 250 + 150 +450) x (0,80) = 920€
Magasin 2 : je ne peux pas lire la suite
