Réponse :
Bonsoir;
Explications étape par étape
1) -8/5-4/5+3/9 = -12/5 +3/9 = (-12*9)/9*5 + 3*5/9*5 = -108/45 +15/45
-93/45 = -31*3/15*3 = -31/15
2) (-2/9 -7/9) -4/5 = -9/9 -4/5 = -1 -4/5 = -5/5 -4/5 = -9/5
3) -2/8 -9/5 = -10/40 - 72/40 = -82/40 = - 41 /20
4)-6/8 -(-5/4 ) = -3/4 +5/4 = +2/4 = 1/2
5) -1/9 -4/6 = -1/9 +2/3 = -1/9 +6 /9= 5/9
6) 2/4 +6/5 = 1/2 +6/5 = 5/10 + 12/10 = 17/10
7) -2/3 -9/5 = -10/15 - 27/15 = -37/15
8) -8/9 +3/2 = -16/18 +27 /18 = 11/18
9) 3/5 -7/2 = 6/10 - 35/10 = - 29/10
10) 6/3 +7/9 = 2 +7/9 = 18/9 +7/9 = 25/9
11) 8/9 +2 = 8/9 + 18/9 = 26/9
12) 9/4 -7/3 +2/4 = 11/4 -7/3 = 33/12 - 28/12 = 5/12
13) 5/9 -1/2 +7/9 = 12/9 -1/2 = 4/3 - 1/2 = 8/6 -3/6 = 5/6
14) 4/2 +5/3 -1/2 = 3/2 +5/3 = 9/6 +10/6 = 19/6
