Réponses

2014-10-31T12:55:34+01:00
7/9 - 1/-27
= 7 x 3 / 9 x 3 - 1/-27
= 21/24 + 1/27
= 22/27

-8/5 + 23/50
= - 8 x 10 / 5 x 10 + 23/50
= - 80/50 + 23/50
= - 57/50

45/15 - 7/3
= 45/15 - 7 x 5 / 3 x 5
= 45/15 - 35/15
= 10/15
= 5 x 2 / 5 x 3
= 2/3

4/11 + 2
= 4/11 + 2 x 11 / 1 x 11
= 4/11 + 22/11
= 26/11

8/-91+-1/7
= - 8/91 - 1 x 13 / 7 x 13
= - 8/91 - 13/91
= - 21/91
= 7 x - 3 / 7 x 13
= - 3/13

5/2 - 45/4 + 2/8
= 5 x 4 / 2 x 4 - 45 x 2 / 4 x 2 + 2/8
= 20/8 - 90/8 + 2/8
= - 68/8
= 4 x - 17/ 4 x 2
= - 17/2

4 - 5/-49 + (- 8/7)
= 4 x 49 / 1 x 49 + 5/49 - 8 x 7 / 7 x 7
= 196/49 + 5/49 - 56/49
= 145/49