Bonjour pourriez vous m’aider pour mon dm de math je n’arrive pas merci : Calculer chaque expression sous la forme la plus simple possible en détaillant les cal

Bonjour,

1) 5/6-5/2*8/15=5/6-5*2*2*2/2*3*3*5=5/6-4/9=15/18-8/18=7/18

2) (6/7-3/4)*8/3=(24/28-21/28)*8/3=3/28*8/3=3*8/3*28=8/28=2/7

4) 7/5-7/3*15/14=7/5-7*3*5/3*7*2=7/5-5/2=14/10-25/10=-11/10

Bonjour,

Calculer chaque expression sous la forme la plus simple possible en détaillant les calculs :

1) 5/6-5/2*8/15

= 5/6 - 40/30

= (5 x 5) / (6 x 5) - 40/30

= 25/30 - 40/30

= - 15/30

= (15 x - 1) / (15 x 2)

= - 1/2

2)(6/7-3/4)*8/3

= [(6 x 4) / (7 x 4) - (3 x 7) / (4 x 7)] x 8/3

= (24/28 - 21/28) x 8/3

= 3/28 x 8/3

= 24/84

= (12 x 2) / (12 x 7)

= 2/7.

3)5/6-8/5/3/4

= 5/6 - 8/5 x 4/3

= 5/6 - 32/15

= (5 x 5) / (6 x 5) - (32 x 2) / (15 x 2)

= 25/30 - 64/30

= - 39/40

4)7/5-7/3*15/14

= 7/5 - 105/42

= 7/5 - (21 x 5) / (21 x 2)

= 7/5 - 5/2

= (7 x 2) / (5 x 2) - (5 x 5) / (2 x 5)

= 14/10 - 25/10

= - 11/10

5)8/5-3/4/9/8

= 8/5 - 3/4 x 8/9

= 8/5 - 24/36

= 8/5 - (12 x 2) / (12 x 3)

= 8/5 - 2/3

= (8 x 3) / (5 x 3) - (2 x 5) / (3 x 5)

= 24/15 - 10/15

= 14/15.