Bonjour
Recopier et compléter par les signes + ; - ou x.
a.8/9 .... 2/3 = 2/9
= 8/9 + 2/3
= 8/9 + 6/9
= 14/9 donc non
= 8/9 x 2/3
= 16/27 non
= 8/9 - 2/3
= 8/9 - 6/9
= 2/9 oui
b.7/2 .... -5/4 = -35/8
= 7/2 x (-5/4)
= -35/8 oui
c.-5/6 .... 9/4 =-15/8
= -5/6 - 9/4
= -20/24 - 54/24
= -74/24
= -37/12 non
= -5/6 + 9/4
= -20/24 + 54/24
= 24/24
= 1 non
= -5/6 x 9/4
= -45/24
= -(3 x 15)/(3 x 8)
= -15/8 oui
2/5 .... 4/15 = 2/15
= 2/5 + 4/15
= 6/15 + 4/15
= 10/15
= 2/3 non
= 2/5 x 4/15
= 8/75 non
= 2/5 - 4/15
= 6/15 - 4/15
= 2/15 oui
