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Bonjour, j'ai besoin d'aide sur cet exercice :

Effectue les calculs en respectant les priorités opératoires.

A = 1/5 x -4/3 + 7/2

B = (3/2 + 3/5) (5/4 - 4/3)

C = 13/7 + (-8/-7) x (-5/-4)

D = 7/3 + 3/2 x -10/21

Merci de bien vouloir m'aider ^^


Répondre :

A=1/5*-4/3+7/2=-4/15+7/2=-8/30+105/30=97/30

B=(3/2+3/5)(5/4-4/3)=(15/10+6/10)(15/12-16/12)=21/10*-1/12=-21/120=-7/40

C=13/7+(-8/-7)*(-5/-4)=13/7+40/28=13/7+10/7=23/7

D=7/3+3/2*-10/21=7/3-30/42=7/3-5/6=14/6-5/6=9/6=3/2
Bonjour :

(-)×(-) = (+)
(-)×(+) = (-)

A = 1/5 × -4/3 + 7/2
A = -4/15 + 7/2
A = -8/30 + 105/30
A = 97/30

B = (3/2 + 3/5)(5/4 - 4/3)
B = (15/10 + 6/10)(15/12 - 16/12)
B = (21/10)(-1/12)
B = -21/10 × 1/12
B = -21×1/12×10
B = -3×7×1/3×4×10
B = -7×1/4×10
B = -7/40

C = 13/7 + (-8/-7)(-5/-4) ---> (-)×(-) =(+)
C = 13/7 + (8/7)(5/4)
C = 13/7 + (8×5/7×4)
C = 13/7 + (4×2×5/7×4)
C = 13/7 + (2×5/7)
C = 13/7 + (10/7)
C = 13/7 + 10/7
C = 32/7

D = 7/3 + 3/2 × -10/21
D = 7/3 + 3×-10/2×21
D = 7/3 - 3×5×2/2×7×3
D = 7/3 - 5/7
D = 49/21 - 15/21
D = 34/21

J’espère t'avoir t'aider