Réponses

2014-02-01T09:56:35+01:00
Calculer sous forme fractionnaire :

A = - 3/5 : 5/2 + 13/40
A = -3/5 x 2/5 + 13/40
A = -6/25 + 13/40
A = -6 x 40 / 25 x 40 + 25 x 13 / 25 x 40
A = -240/1000 + 325/1000
A = 85/1000
A = 5 x 17 / 5 x 200
A = 17/200

B = 8/3 + 2/3 : 5/7

B = 8/3 + 2/3 x 7/5
B = 8/3 + 14/15
B = 8 x 5 / 3 x 5 + 14/15
B = 40/15 + 14/15
B = 54/15
B = 3 x 18 / 3 x 5
B = 18/5
2014-02-01T10:04:10+01:00
A = - 3/5 : 5/2 + 13/40
= -3/5 x 2/5 + 13/40
= -6/25 + 13/40
= -240/1 000 + 325/1 000
= 85/1 000
= 17/200 <== Sous forme simplifié

B = 8/3 + 2/3 : 5/7
= 8/3 + 2/3 x 7/5
= 8/3 + 14/15
= 40/15 + 14/15
= 54/15
= 18/5 <== Sous forme simplifié