Réponse :
1) compléter
40/24 = 5/.... ⇔ 40/24 = 5/a ⇔ 40 x a = 24 x 5 ⇔ a = 24 x 5/40 = 3
donc 40/24 = 5/3
6/7 = ..../63 ⇔ 6/7 = a/63 ⇔ 7 x a = 6 x 63 ⇔ a = 6 x 63/7 = 54
donc 6/7 = 54/63
14/21 = 2/.... ⇔ 14/21 = 2 x 7/3 x 7 = 2/3
Donc 14/21 = 2/3
...../9 = 28/36 ⇔ 4 x 7/4 x 9 = 7/9
donc 7/9 = 28/36
16/.... = 2/5 ⇔ 2 x 8/5 x 8 = 16/40
donc 16/40 = 2/5
9/4 = 81/.... ⇔ 9 x 9/4 x 9 = 81/36
donc 9/4 = 81/36
Explications étape par étape
