Bonjour je n’arrive pas à comprendre les deux exercices :/

Réponse :

Explications étape par étape

Bonjour

A = 2/7 x 9/4

A = 2/4 x 9/7

A = 2/(2 x 2) x 9/7

A = 1/2 x 9/7

A = 9/(2 x 7)

A = 9/14

B = 5 x 7/15

B = 5/15 x 7

B = 5/(3 x 5) x 7

B = 1/3 x 7

B = 7/3

C = 36/35 x 21/12

C = 36/12 x 21/35

C = (3 x 12)/12 x (3 x 7)/(5 x 7)

C = 3 x 3/5

C = 9/5

A = 1/2 - 1/3 - 1/6

A = (1 x 3)/(2 x 3) - (1 x 2)/(3 x 2) - 1/6

A = 3/6 - 2/6 - 1/6

A = (3 - 2 - 1)/6

A = 0

B = 7/4 - 15/4 x 1/5

B = 7/4 - 15/5 x 1/4

B = 7/4 - (3 x 5)/5 x 1/4

B = 7/4 - 3 x 1/4

B = 7/4 - 3/4

B = 4/4

B = 1

C = (3 - 2/9)/(5/6 - 5/9)

C = [(3 x 9)/9 - 2/9] / [(5 x 3)/(6 x 3) - (5 x 2)/(9 x 2)]

C = (27/9 - 2/9) / (15/18 - 10/18)

C = 25/9 / 5/18

C = 25/9 x 18/5

C = 25/5 x 18/9

C = (5 x 5)/5 x (2 x 9)/9

C = 5 x 2

C = 10