Réponse :
Bonsoir
Explications étape par étape
A) 35/26 × 13/70
= 35 × 13/26×70
= 35 × 13 / 13 × 2 × 35 × 2
= 1 × 1 / 2 × 2
= 1/4
B) 45/24 × 8/9
= 45 × 8/24 × 9
= 9 × 5 × 8 / 8× 3 × 9
= 5/3
C) 63/36 × 12/81
= 63 × 12 / 36 × 81
= 9 × 7 × 6 × 2/ 9 × 6 × 9 × 9
= 14/81
D) 32/27 × 54/28
= 32 × 54/27 × 28
= 8 × 2 × 2 × 9 × 3 × 2/ 9 × 3 × 7 × 2 × 2
= 16/7