Réponses

2013-10-27T16:52:17+01:00
(21/7+5/7)*14/39
=26/7*14/39
=26/1*2/39
=52/39

4/15*9/8-11/6
= 1/5*3/2-11/6
= 3/10-11/6
= 9/30-55/30
=-46/30