bonjour qui peux m aider svp sur ces deux exercices je galère vrm svp​

exercice 7:

A=11×7/5×2= 77/10

B= 13×9/22 =117/22

C=3×1,5/7×2=9/14

D=18/5

exercice 8:

A=5×3/7×3 + 11/21 =15/21

B=13×3/3×3 - 7/9 =32/9

C=9×2/12×2 + 7×3/8×3 = 39/24 = 13/8

D= 8×5/4×5 - 1×2/10×2 = 42/20 =21/10