Réponse :
Explications étape par étape
Bjr,
3/17 -(-7/51) = 3/17 +7/51=
3/17 = (3*3) / (3*17) = 9/51
9/51 +7/51 = 16/51
2/7 -5/14 -1/28 =
8/28 -10/28 -1/28 = -3/28
-3 - 7/12 =
-3 = -3/1 = (-3*12) / (1*12)
-36/12 -7/12 = -43/12
1-1/2 +1/3 -1/4 +1/5 =
1-1/2 = 2/2-1/2 = 1/2
1/2 +1/3 = 3/6 +2/6 = 5/6
5/6 +1/4 = (5*4)/(6*4) + (6*1) / (6*4 ) =
20/24 + 6/24 = 26/24 = 13/12
13/12 +1/5 = (13*5)/(12*5) + 12 / ( 12*5) =
25/ 120 = 5/24
e)
5/39 -7/13 = 5/39 - 21/39 = -16/39
8/13 -(-16/39) =8/13 + 16/39 = 24/39 + 16/39 = 40/39
☺
