Bonjour
Ecrire chacun des nombres suivants sous la forme d´une fraction irréductible :
A = - 3/35 + 4/5 - 3/4
A = (- 3 x 8) / (35 x 8) + (4 x 56) / (5 x 56) - (3 x 70) / (4 x 70)
A = - 24/280 + 224/280 - 210/280
A = - 10/280
A = (10 x - 1) / (10 x 28)
A = - 1/28
B = (2/7 + 5/21) : (5/9 - 1/3)
B = [(2 x 3) / (7 x 3) + 5/21] : [5/9 - (1 x 3) / (3 x 3)]
B = (6/21 + 5/21) : (5/9 - 3/9)
B = 11/21 : 2/9
B = 11/21 x 9/2
B = 99/42
B = (3 x 33) / (3 x 14)
B = 33/14
C = (2 + 1/5) : (3/15 - 7)
C = [(2 x 5) / (1 x 5) + 1/5] : [3/15 - (7 x 15) / (1 x 15)]
C = (10/5 + 1/5) : (3/15 - 105/15)
C = 11/5 : - 102/15
C = 11/5 x - 15/10
C = - 165/50
C = (5 x - 33) / (5 x 10)
C = - 33/10.
