Effectuer chacon des calculs suivants. On donnera les résultats sous la forme d'une fraction simplifiée au maximum : a) 7sur6 + (8sur3 - 2sur3) = b) (17sur4 - 5

bonjour

a) 7/6 + ( 8/3 - 2/3)= 7/6 + 6/3 = 7/6 - 12/6 = - 5/6

b) ( 17/4 - 5/4) - 3/4 = 12/4 - 3/4 = 9/4

c= (5/2 - 1/4) + ( 2 - 7/8) = (10/4 - 1/4) + ( 16/8 - 7/8) 
c = 9/4 + 9/8 = 18/8 + 9/8 = 27/8

d) ( 8/3 + 1/9) - ( 2/3 + 4/3) = ( 24/9 + 1/9) - 6/3 = 25/9 - 6/3 = 25/9 - 18/9 = 7/9

a) 7/6 + (8/3 - 2/3)
= 7/6 + 6/3
= 7/6 + 6 x 2 / 3 x 2
= 7/6 + 8/6
= 15/6
= 3 x 5 / 3 x 2
= 5/2

b) (17/4 - 5/4) - 3/4
= 12/4 - 3/4
= 9/4

c) (5/2 - 1/4) + (2 - 7/8)
= (5 x 2 / 2 x 2 - 1/4) + (2 x 8 / 1 x 8 - 7/8)
= (10/4 - 1/4) + (16/8 - 7/8)
= 9/4 + 9/8
= 9 x 2 / 4 x 2 + 9/8
= 18/8 + 9/8
= 27/8

d) (8/3 + 1/9) - (2/3 + 4/3)
= (8 x 3 / 3 x 3 + 1/9) - (2 x 3 / 3 x 3 + 4 x 3 / 3 x 3)
= (24/9 + 1/9) - (6/9 + 12/9)
= 25/9 - 28/9
= - 3/9
= 3 x - 1 / 3 x 3
= - 1/3