J'ai besoin d'aide svp Ecrire sous la forme d'une fraction irréductible A=4/3x7/5 B=2/5x5/9 C=7/8x6/5 D=-2/5x3/-7x-7/2 E=7x1/11x3/14 F=6/35x14/3x1/2

Ecrire sous la forme d'une fraction irréductible

A = 4/3 x 7/5
A = 28/15

B = 2/5 x 5/9
B = 10/45
B = 5 x 2 / 5 x 9
B = 2/9

C = 7/8 x 6/5
C = 42/40
C = 2 x 21 / 2 x 20
C = 21/20

D = - 2/5 x 3/ -7 x - 7/2
D = 6/35 x - 7/2
D = - 42/70
D = 14 x - 3 / 14 x 5
D = - 3/5

E = 7 x 1/11 x 3/14
E = 7/11 x 3/14
E = 21/154
E = 7 x 3 / 7 x 22
E = 3/22

F = 6/35 x 14/3 x 1/2
F = 84/105 x 1/2
F = 84/210
F = 42 x 2 / 42 x 5
F = 2/5

A = 4/3 X 7/5 = 28/15 

B = 2/5 X 5/9 = 10/45 = 2/9

C = 7/8 X 6/5 = 42/ 40 = 21/20

D = - 2/5 x 3/ -7 x - 7/2 = 6/35 X -7/2 = -42/70 = 14X -3/14 = -3/5

E = 7 X 1/11 X 3/14 = 7/11 X 3/14 = 21/154 = 3/22

F = 6/35 x 14/3 x 1/2 = 84/105 x 1/2 = 84/210 = 28/70 = 4/10 = 2/5