👤

Salut, vous pouvez m'aider pour mon dm de mathématiques svp, merci, bon lundi de Pâques

On donne: a=2/3 b=-3 c=-3/4

Exprimer sous forme fractionnaire: a+c, a+b, b+c, c-a, a-b, c-b


Répondre :

Bonjour,

On donne: a=2/3 b=-3 c=-3/4

Exprimer sous forme fractionnaire :

a + c

= 2/3 + (- 3/4)

= 2/3 - 3/4

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

= 8/12 - 9/12

= 1/12

a + b

= 2/3 + (- 3)

= 2/3 - 3

= 2/3 - (3 x 3) / (1 x 3)

= 2/3 - 9/3

= - 7/3

b + c

= - 3 + (- 3/4)

= - 3 - 3/4

= (- 3 x 4) / (1 x 4) - 3/4

= - 12/4 - 3/4

= - 15/4

c - a

= - 3/4 - 2/3

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

= - 9/12 - 8/12

= - 17/12

a - b

= 2/3 - (- 3)

= 2/3 + 3

= 2/3 + (3 x 3) / (1 x 3)

= 2/3 + 9/3

= 11/3

c - b

= - 3/4 - (- 3)

= - 3/4 + 3

= - 3/4 + (3 x 4) / (1 x 4)

= - 3/4 + 12/4

= 9/4

Réponse :

On donne: a=2/3 b=-3 c=-3/4

Exprimer sous forme fractionnaire:

a+c = 2/3+(-3/4) = 2/3-3/4 = (2*4-3*3)/3*4 = (8-9)/12 = - 1/12

a+b= 2/3+(-3) = 2/3-3 = (2-9)/3 = -7/3

b+c= -3+(-3/4) = -3-3/4 = (-3*4 -3)/4 = (-12-3)/4 =-15/4

c-a =-3/4-2/3 =(-3*3 -2*4)/4*3 = (-9-8)/12 =-17/12

a-b=  2/3-(-3) = 2/3+3 =(2+9)/3 =11/3

c-b  =-3/4-(-3) =-3/4+3 =(-3/4+12)/4 = 9/4

Explications étape par étape