Réponses

2013-12-11T19:45:08+01:00
15/49 x (-28/-35)
= \frac{15*(-28)}{49*(-35)} = \frac{3*4}{7*7} = \frac{12}{49}

* est le signe de la multiplication
2013-12-11T19:50:27+01:00
= 15 / 49 x ( -28 / -35 )
= 15 / 49 x 28 / 35
= 420 / 1 715
= 12/49