Chapitres
- 01. Exercice 1
- 02. Exercice 2
- 03. Exercice 3
Exercice 1
Dans chacun des cas suivants, calculez la valeur de a+b-c :
¤ a = 1/2 ; b = 3/4 ; c = 1/4.
1/2 + 3/4 - 1/4
= 2/4 + 3/4 - 1/4
= 5/4 - 1/4
= 4/4
= 1.
¤ a = 7/6 ; b = 10/3 ; c = 5/6.
7/6 + 10/3 - 5/6
= 7/6 + 20/6 - 5/6
= 27/6 - 5/6
= 22/6 = 11/3.
¤ a = 1/3 ; b = 1/9 ; c = 1/27.
1/3 + 1/9 - 1/27
= 9/27 + 3/27 - 1/27
= 12/27 - 1/27
= 11/27
¤ a = 2/5 ; b = 13/15 ; c = 2/5.
2/5 + 13/15 - 2/5
= 6/15 + 13/15 - 6/15
= 19/15 - 6/15
= 13/15
Exercice 2
Simplifie lorsque c'est possible puis calcule les produits :
a. 2/3 x 3/7 x 5/11 = 2 x 3 x 5 = 2 x 5 = 10
3 x 7 x 11 7 x 11 77
b. 3/5 x 13/7 x 5/2 = 3 x 13 x 5 = 3 x 13 = 39
5 x 7 x 2 7 x 2 14
c. 3/2 x 2/5 x 3/11 = 3 x 2 x 3 = 3 x 3 = 9
2 x 5 x 11 5 x 11 55
d. 6/5 x 1/14 x 7/3 = 3 x 3 x 1 x 7 = 3 = 3 5 x 7 x 2 x 3 x 1 5 x 2 10
Exercice 3
Calcule et donne le résultat sous la forme d'une fraction la plus simple possible :
a. 5 x 2/3 - 1/3
= 5/1 x 2/3 -1/3
= 15 x 2 -1/3
3 x 3
= 30/9 -1/3
= 10/3-1/3
= 9/3
= 3/1 = 3.
b. 7/4 - 3/4 x 3/2
= 7/4 - 9/8
= 14/8 - 9/8
= 5/8
c. (5/6 + 7/12) x 3/5
= (10/12 + 7/12) x 3/5
= 17/12 x 3/5
= 17 x 3 = 17/20
3 x 4 x 5
d. 3/4 x 2/9 + 28/15 x 25/14
= 3 x 2 x 1 + 14 x 2 x 5 x 5
2 x 2 x 3 x 3 5 x 3 x 14
= 1 + 2 x 5
2 x 3 3
= 1/6 + 10/3
= 1/6 + 20/6
= 21/6 = 7/2
Comment trouver le bon cour de math ?
Calcule :
A = 7/2 / 5 = ( 7 / 5 ) / 5
5 2 ( 2 ) 2
= 7 x 1 x 2
2 x 5 x 5
= 7
25
B = 3 / 1/2 = ( 3 / 4 ) / ( 1 / 6 )
4/9 6 ( 9 ) ( 2 )
= (3 x 9 ) / ( 1 x 1 )
( 4) ( 2 6 )
= 27 / 1
4 12
= 27/4 x 12
= 27 x 4 x 3
4
= 81.
Si vous désirez une aide personnalisée, contactez dès maintenant l’un de nos professeurs !