Sagot :

Sylvia38

Réponse :

Bonjour

Explications étape par étape

A = 12/5 - 3/5 × 7/9

A = 12/5 - (7×3)/(5×9)

A = 12/5 - 21/45

A = (12×9)/(5×9) - 21/45

A = 108/45 - 21/45

A = 87/45

A = (29×3)/(15×3)

A = 29/15

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

B =(2/3 - (3×3)/3) : 1/9

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

B = (-7/3) : 1/9

B = (-7/3) × 9

B = (-7×9)/3

B = -63/3

B = -21