Bonsoir c’est pour les exercices 4et 5 Merci d’avance c’est pour demain svp

Bonsoir,

Exercice 4

a) 3/7 + 15/7 × 3/2

a = 3/7 + (15 × 3)/(7 × 2)

a = 3/7 + 45/14 = 6/14 + 45/14

a = 51/14

b) 9/5 × (1/4 - 5/12)

b = 9/5 × (3/12 - 5/12)

b = 9/5 × (-2/12)

b = 9 × (-2) / 5 × 12

b = -18/60 = -9/30 = -3/10

c) (3/8 + 7/5) ÷ (9/4 - 5/3)

c = (15/40 + 56/40) ÷ (27/12 - 20/12)

c = (71/40) ÷ (7/12)

c = 71/40 × 12/7

c = 71 × 12 / 40 × 7

c = 852/280 = 426/140 = 213/70

Exercice 5

A = 5 × 3/4 - 2/7 ÷ 4/3

A = 15/4 - 2/7 × 3/4

A = 15/4 - 6/28

A = 105/28 - 6/28 = 99/28

Bonne nuit !

Réponse :

4) a) 3/7 + 15/7 x 3/2       ordre de priorité la x

      = 3/7 + 45/14 = 3 x 2/14 + 45/14 = 6/14 + 45/14 = 51/14

   b) 9/5 x (1/4 - 5/12 = 9/5 x (3/12 - 5/12) = 9/5 x -2/12 = - 18/60 = - 3/10

   c) (3/8 + 7/5) : (9/4 - 5/3) = (15/40 + 56/40) : (27/12 - 20/12)

        = 71/40 : 7/12

        = 71 x 12/7 x 40 = 71 x 3/7 x 10 = 213/70

5) A = 5 x 3/4 - 2/7 ; 4/3 , on effectue les  x et les : avant les + et les -

       = 15/4 - 6/28 = 105/28 - 6/28 = 99/28

Explications étape par étape