bonjour, pouvez vous m'aidez à calculer ces fractions svp​

Bonjour

A = 3/8 + 2/5

A = (3 x 5) / (8 x 5) + (2 x 8) / (5 x 8)

A = 15/40 + 16/40

A = 31/40

B = 4/7 - 8/5

B = (4 x 5) / (7 x 5) - (8 x 7) / (5 x 7)

B = 20/35 - 56/35

B = - 36/35

C = 3/5 x 7/11

C = 21/55

D = 3/5 : 7/11

D = 3/5 x 11/7

D = 33/35

E = 1/3 + 2/5 x 3/4

E = 1/3 + 6/20

E = (1 x 20) / (3 x 20) + (6 x 3) / (20 x 3)

E = 20/60 + 18/60

E = 38/60

E = (2 x 19) / (2 x 30)

E = 19/30

F = (1/3 + 2/5) x 3/4

F = [(1 x 5) / (3 x 5) + (2 x 3) / (5 x 3)] x 3/4

F = (3/15 + 6/15) x 3/4

F = 9/15 x 3/4

F = 27/60

F = (3 x 9) / (3 x 20)

F = 9/20.