Réponse :
Bonsoir,
A = 197 x 21
= 197 x (17 + 4)
= 197 x 17 + 197 x 4
= 3349 + 788
= 4137 .
D = 197 x 51
= 197 x (17 + 17 + 17)
=197 x 17 + 197 x 17 + 197 x 17
= 3349 + 3349 + 3349
= 10047 .
B = 197 x 13
= 197 x (17 - 4)
= 197 x 17 - 197 x 4
= 3349 - 788
= 2561 .
E = 197 x 9
= 197 x (13 - 4)
= 197 x 12 - 197 x 4
= 2561 - 788
= 1773 .
C = 197 x 34
= 197 x (17 + 17)
= 197 x 17 + 197 x 17
= 3349 + 3349
= 6698 .
F = 197 x 42
= 197 x (51 - 9)
= 197 x 51 - 197 x 9
= 10047 - 1773
= 8274 .
b.
197 x 8 = 197 x (4 + 4) = 197 x 4 + 197 x 4
= 788 + 788 = 1576 .
197 x 5 = 197 x (4 + 1) = 197 x 4 + 197 x 1
= 788 + 197 = 985 .
197 x 18 = 197 x (17 + 1)
= 197 x 17 + 197 x 1
= 3349 + 197 = 3546 .
En espérant t'avoir aidé.
