Bonjour j'aurrai besoin d'aide svp : Calculer et donner le résultat sous la forme d'une fraction irréductible : A = 2/3 + 7/3 × -9/4 B = (2 - 5/8) ÷ 3/4 C = (4/

Bonsoir,

Calculer et donner le résultat sous la forme d'une fraction irréductible :

A = 2/3 + 7/3 × -9/4

A = 2/3 - 63/12

A = (2 x 4) / (3 x 4) - 63/12

A = 8/12 - 63/12

A = - 55/12

B = (2 - 5/8) ÷ 3/4

B = [(2 x 8) / (1 x 8) - 5/8] : 3/4

B = (16/8 - 5/8) : 3/4

B = 11/8 x 4/3

B = 44/24

B = (4 x 11) / (4 x 6)

B = 11/6

C = (4/5 - 2) × (3/4 - 2/3)  

C = [4/5 - (2 x 5) / (1 x 5)] x [(3 x 3) / (4 x 3) - (2 x 4) / (3 x 4)]

C = (4/5 - 10/5) x (9/12 - 8/12)

C = - 6/5 x 1/12

C = - 6/60

C = (6 x - 1) / (6 x 10)

C = - 1/10

D = 2/13 - 5/13 ÷ 10/16

D = 2/13 - 5/13 x 16/10

D = 2/13 - 80/130

D = (2 x 10) / (13 x 10) - 80/130

D = 20/130 - 80/130

D = - 60/130

D = (10 x - 6) / (10 x 13)

D = - 6/13.

[tex]A=\dfrac 23+\dfrac 73\times\dfrac{-9}4=\dfrac 8{12}-\dfrac{63}{12}=-\dfrac{55}{12}[/tex]

[tex]B=\left(2-\dfrac 58\right)\div\dfrac 34=\left(\dfrac{16}8-\dfrac 58\right)\times\dfrac 43=\dfrac {11}8\times\dfrac 43=\dfrac{11\times 4}{4\times 2\times 3}=\dfrac {11}6[/tex]

[tex]C=\left(\dfrac 45-2\right)\times\left(\dfrac 34-\dfrac 23\right)=\left(\dfrac 45-\dfrac {10}5\right)\times\left(\dfrac 9{12}-\dfrac 8{12}\right)=-\dfrac 65\times\dfrac 1{12}=-\dfrac 6{5\times 2\times 6}=-\dfrac 1{10}[/tex]

[tex]D=\dfrac 2{13}-\dfrac 5{13}\div\dfrac{10}{16}=\dfrac 2{13}-\dfrac 5{13}\div\dfrac 5{8}=\dfrac 2{13}-\dfrac 8{13}=-\dfrac 6{13}[/tex]