Bonjour,
a. 35 et 21
35/5 = 7
=> 5*7
21/ 3 = 7
=> 3*7
PGCD: 7
b. 245 et 490
245/5 = 49
49/7 = 7
=> 5*7*7
490/ 2 =245
245/5 = 49
49/7 = 7
=> 2*5 *7 *7
PGCD: 5*7*7 = 245
c. 5781 et 2586.
5781/ 3 = 1927
1927/ 41 = 47
=> 3*41 * 47
2586/2 = 1293
1293/3 = 431
=> 2*3 * 431
PGCD: 3