Merci de répondre très rapidement Calculer sous la forme d’une fraction irréductible ou d’un entier

Bonjour

I = 12/5 - 3/5 x 7/9

I = 12/5 - 21/45

I = (12 x 3) / (5 x 3) - (3 x 7) / (3 x 15)

I = 36/15 - 7/15

I = 29/15

J = 7/3 - 4/3 : 2/5

J = 7/3 - 4/3 x 5/2

J = (7 x 2) / (3 x 2) - 20/6

J = 14/6 - 20/6

J = - 6/6

J = - 1

K = (2/3 - 3) : 1/9

K = [2/3 - (3 x 3) / (1 x 3)] : 1/9

K = (2/3 - 9/3) : 1/9

K = - 7/3 x 9

K = 63/3

K = (3 x 21) / (3 x 1)

K = 21

L = 1/3 - 1/3 x 4/7

L = (1 x 7) / (3 x 7) - 4/21

L = 7/21 - 4/21

L = 3/21

L = (3 x 1) / (3 x 7)

L = 1/7

M = 6/5 : (1/15 - 1/5)

M = 6/5 : [1/15 - (1 x 3) / (5 x 3)]

M = 6/5 : (1/15 - 3/15)

M = 6/5 : - 2/15

M = 6/5 x - 15/2

M = - 90/10

M= (10 x - 9) / (10 x 1)

M = - 9

N = 3/5 - 1/5 x (5/2 + 2)

N = 3/5 - 1/5 x [5/2 + (2 x 2) / (1 x 2)]

N = 3/5 - 1/5 x (5/2 + 4/2)

N = 3/5 - 1/5 x 9/2

N = 3/5 - 9/10

N = (3 x 2) / (5 x 2) - 9/10

N = 6/10 - 9/10

N = - 3/10

O = 5 + (1 + 1/8) : 3/4

O = 5 + [(1 x 8) / (1 x 8) + 1/8] x 4/3

O = 5 + (8/8 + 1/8) x 4/3

O = 5 + 9/8 x 4/3

O = 5 + 36/24

O = (5 x 2) / (1 x 2) +  (12 x 3) /(12 x 2)

O = 10/2 + 3/2

O = 13/2.