Bonsoir
a) 5 sur 6 + 8 sur 3 =
= 5/6 + 8/3
= 5/6 + (8 x 2)/(3 x 2)
= 5/6 + 16/6
= 21/6
= (3 x 7)/(3 x 2)
= 7/2
b) 4 sur 5 +7 sur 20=
= (4 x 4)/(5 x 4) + 7/20
= 16/20 + 7/20
= 23/20
c)2 sur 3+ 5 sur 9=
= (2 x 3)/(3 x 3) + 5/9
= 6/9 + 5/9
= 11/9
d) 11 sur 3 - 4 sur 30=
= (11 x 10)/(3 x 10) - 4/30
= 110/30 - 4/30
= 106/30
= (53 x 2)/(15 x 2)
= 53/15
e)5 - 3 sur 4=
= (5 x 4)/4 - 3/4
= 20/4 - 3/4
= 17/4
f)4 sur 50 - 2 sur 200=
= (4 x 2)/(50 x 2) - 2/(2 x 100)
= 8/100 - 1/100
= 7/100
