Réponse :
A = 7n+4
B = 2n² - 12
C = n² + 4
a) si n = 4
A = 7*4 + 4 = 32
B= 2(4²) - 12 = 32 - 12 = 20
C = (4)² + 4 = 16 + 4 = 20
si n = 7
A = 7*7 + 4 = 53
B= 2(7²) - 12 = 98 - 12 = 86
C = (7)² + 4 = 49 + 4 = 53
b) on remarque que
si n =4 alors B = C
si n = 7 alors A = C
