Réponse:
B = (27)^2 - (3)^2
B = 27×27 - 3×3
B = 729 - 9
B = 720
C = (46)^2 - (44)^2
C = 46 × 46 - 44 × 44
C = 2116 - 1936
C = 180
D = (999)^2 - 1
D = 998001 - 1
D = 998000
