calcumer sous la forme la plus simple -13sur7+3sur7:5sur3? 3sur4+1sur2x(2sur3-1) Svp donner la répond j'y arriv

Calculer sous la forme la plus simple possible :

- 13/7 + 3/7 : 5/3
= - 13/7 + 3/7 x 3/5
= - 13/7 + 9/35
= - 13 x 5 / 7 x 5 + 9/35
= - 65/35 + 9/35
= - 56/35
= 7 x - 8/ 7 x 5
= - 8/5

3/4 + 1/2 x (2/3 - 1)
= 3/4 + 1/2 x (2/3 - 1 x 3 / 1 x 3)
= 3/4 + 1/2 x (2/3 - 3/3)
= 3/4 + 1/2 x - 1/3
= 3/4 - 1/6
= 3 x 6 / 4 x 6 - 1 x 4 / 6 x 4
= 18/24 - 4/24
= 14/24
= 2 x 7 / 2 x 12
= 7/12