Réponses

2014-03-30T17:10:05+02:00
a) 11/1 -1/5 + 3 = 11 x 5 / 1 x 5 - 1/5 + 3 x 5 / 1 x 5 = 55/5 -1/5 + 15/5 = 70/5 - 1/5 = 69/5

b) 9/24 + 3/4 + 5 = 9/24 + 3 x 6 / 4 x 6 + 5 x 24 / 1 x 24 = 9/24 + 18/24 + 120/24 = 147/24 = 3 x 49 / 3 x 8 = 49/8

c) 13/11 + 2 = 13/11 + 2 x 11 / 1 x 11 = 13/11 + 22/11 = 35/11

d) 1/5 + 1/7 = 1 x 7 / 5 x 7 + 1 x 5 / 7 x 5 = 7/35 + 5/35 = 12/35

e) 1/4 + 7/5
= 1 x 5 / 4 x 5 + 7 x 4 / 5 x 4 = 5/20 + 28/20 = 33/20
2014-03-30T17:12:27+02:00
A) 11 sur 1 -1 sur 5 +3 
11/(1-1)/(5+3)
= 11/(0x8)    impossible

b) 9 sur 24 +3 sur 4+5
9/(24+3)/(4+5)
= 9/(27x9)
= 1/27

c) 13 sur 11 +2 
= 3/(11+2)
= 13/13
= 1

d) 1 sur 5 +1 sur 7
= 1/(5+1)/7
= 1/(6x7)
= 1/42

e) 1 sur 4 + 7 sur 5
= 1/(4+7)/5
= 1/(11x5)
= 1/55