Répondre :
84 = 1 x 57 + 27
57 = 2 x 27 + 3
27 = 3 x 9 + 0
pgcd (57 ; 84) = 3
120 = 2 x 48 + 24
48 = 2 x 24 + 0
pgcd (120 ; 48) = 24
57 = 2 x 27 + 3
27 = 3 x 9 + 0
pgcd (57 ; 84) = 3
120 = 2 x 48 + 24
48 = 2 x 24 + 0
pgcd (120 ; 48) = 24