Calculer et donner les résultats sous forme de fraction irréductible:

A= 1 + 5 x 7 B= ( 3 + 7 ) x 3
5 7 25 5 15 12

C= 4 x 15 + 28 x 6 D= ( 5 + 3 ) x ( 7 - 5 )
5 3 6 7 2 4 2 6

E= 2 x ( 5 + 5 + 14 )
9 3 9 12

1
A=1/5+5x7x3/7x5x5x3x4 A=1/5x1/20 A=1x4/5x4+1/20 A=4/20+1/20 A=5/20 A=5x1/5x4 A=1/4
heeuu j'comprend pas là!?

Réponses

2014-02-22T23:27:17+01:00
A = 1/5 + 5x7/7x25
A = 1/5 + 35/175
A = 1/5 + 1/5
A = 2/5

B = ( 9/15 + 7/15 ) x 3/12
B = 16/15 x 3/12
B = 4/9

C = 4 + 4 
C = 8

D = ( 5/2 + 3/4 ) x ( 7/2 - 5/6 )
D = ( 10/4 + 3/4 ) x ( 21/6 - 5/6 )
D = 13/4 x 16/6
D = 52/6
D = 26/3

E = 2/9 x ( 5/3 + 5/9 + 14/12 )
E = 2/9 x ( 5/3 + 5/9 + 7/6 )
E = 2/9 x ( 30/18 + 10/18 + 21/18 )
E = 2/9 x 61/18
E = 61/81