Pouvez vous m’aider à mon dm de math ( exercice 1 et 2)svp je dois le rendre demain, mercii d’avance

Bonjour,

1)

A = - 7 x 3 - (- 4) x (- 2)

A = - 7 x 3 - 8

A = - 21 - 8

A = - 29

B = - 7 x (3 - (- 4)) x (- 2)

B = - 7 x (3 + 4) x (- 2))

B = 7 x (7 x (- 2))

B = 7 x (- 14)

B = - 98

C = - 7 x [3 - (- 4) x (- 2)]

C = - 7 x (3 - 8)

C = - 7 x (- 5)

C = 35

D = (- 7 x 3 - (- 4)) x (- 2)

D = (- 21 + 4) x (- 2)

D = - 17 x (- 2)

D = 34

E = - 7 x 3 - (- 4) : (- 2)

E = - 21 - 2

E = - 23

F = - 7 x (3 - (- 4) : (- 2))

F = - 7 x (3 - 2)

F = - 7 x 1

F = - 7

2)

a = - 3/7 ; b = 2/3 ; c = 4/7

a + b x c

= - 3/7 + 2/3 x 4/7

= - 3/7 + 8/21

= (- 3 x 3) / (7 x 3) + 8/21

= - 9/21 + 8/21

= - 1/21

a x b - c

- 3/7 x 2/3 - 4/7

= - 6/21 - (4 x 3) / (7 x 3)

= - 6/21 - 12/21

= - 18/21

(a - b) x c

(- 3/7 - 2/3) x 4/7

= [(- 3 x 3) / (7 x 3) - (2 x 7) / (3 x 7)] x 4/7

= (- 9/21 - 14/21) x 4/7

= - 23/21 x 4/7

= - 92/147

(b - 3) x a + c

(2/3 - 3) x - 3/7 + 4/7

= [2/3 - (3 x 3) / (1 x 3)] x - 3/7 + 4/7

= (2/3 - 9/3) x - 3/7 + 4/7

= - 7/3 x - 3/7 + (4 x 3) / (7 x 3)

= 21/21 + 12/21

= 33/21

= (3 x 11) / (3 x 7)

= 11/7.