Calculați: a (28; 42; 63); b [28; 42; 63].

(28;42;63)
28 = 2² × 7
42 = 2 × 3 × 7
63 = 3² × 7
c.m.m.d.c = 7
[28;42;63]
c.m.m.m.c = 2² × 3² × 7 = 36 × 7 = 252