Bonjour
Effectuer les calculs suivants, puis donner le résultat sous forme de fraction irréductible ou de nombre entier :
15/7 - 3/7 = 12/7
8/9 - 5/7 = (8 x 7) / (9 x 7) - (5 x 9) / (7 x 9) = 56/63 - 45/63 = 13/63.
3/4 + 5/12 = (3 x 3) / (4 x 3) + 5/12 = 9/12 + 5/12 = 14/12 = (2 x 7) / (2 x 6) = 7/6
2/3 + 5/6 + 7/5
= (2 x 10) / (3 x 10) + (5 x 5) / (6 x 5) + (7 x 6) / (5 x 6)
= 20/30 + 25/30 + 42/30
= 87/30
= (3 x 29) / (3 x 10)
= 29/10
5/4 + 5/7 - 9/14
= (5 x 7) / (4 x 7) + (5 x 4) / (7 x 4) - (9 x 2) / (14 x 2)
= 35/28 + 20/28 - 18/28
= 37/28
33/24 + 28/35
= (33 x 35) / (24 x 35) + (28 x 24) / (35 x 24)
= 1 155/840 + 672/840
= 1 827/840
= (21 x 87) / (21 x 40)
= 87/40
35 x 4/7 = 140/7 = (7 x 20) / (7 x 1) = 20.
11 x 42/3 = 462/3 = (3 x 154) / (3 x 1) = 154.
4 x 13/18 = 52/18 = (2 x 26) / (2 x 9) = 26/9.
