Réponse :
Explications étape par étape
Bonjour
Calculer :
A = 1/a + 2/b + 3/c
B = b/a + a/b
C = a/(b + c)
D = a - c/(a + b)
a = 3 ; b = 5 ; c = 7
A = 1/3 + 2/5 + 3/7
A = 35/105 + 42/105 + 45/105
A = 122/105
B = 5/3 + 3/5
B = 25/15 + 9/15
B = 34/15
C = 3/(5 + 7)
C = 3/12
C = 1/4
D = 3 - 7/(3 + 5)
D = 3 - 7/8
D = 24/8 - 7/8
D = 17/8
a = -2 ; b = 2/5 ; c = 1
A = 1/-2 + 2/(2/5) + 3/1
A = -1/2 + 2 x 5/2 + 3
A= -1/2 + 5 + 3
A = -1/2 + 8
A = -1/2 + 16/2
A = 15/2
B = (2/5)/(-2) + (-2)/(2/5)
B = 2/5 x (-1/2) - 2 x 5/2
B = -1/5 - 5
B = -1/5 - 25/5
B = -26/5
C = 1/(2/5 + 1)
C = 1/(2/5 + 5/5)
C = 1/(7/5)
C = 1 x 5/7
C = 5/7
D = -2 - 1/(-2 + 2/5)
D = -2 - 1/(-10/5 + 2/5)
D = -2 - 1/(-8/5)
D = -2 - 1 x (-5/8)
D = -16/8 + 5/8
D = -11/8
a = 1/2 ; b = -1/3 ; c = 3/5
A = 1/(1/2) + 2/(-1/3) + 3/(3/5)
A = 2 - 6 + 3 x 5/3
A = -4 + 5
A = 1
B = (-1/3)/(1/2) + (1/2)/(-1/3)
B = -1/3 x 2 - 1/2 x 3
B = -2/3 - 3/2
B = -4/6 - 9/6
B = - 13/6
C = (1/2)/(-1/3 + 3/5)
C = 1/2 / (-5/15 + 9/15)
C = 1/2 / (4/15)
C = 1/2 x 15/4
C = 15/8
D = 1/2 - (3/5)/(1/2 + (-1/3))
D = 1/2 - 3/5 / (3/6 - 2/6)
D = 1/2 - 3/5 / (1/6)
D = 1/2 - 3/5 x 6
D = 1/2 - 18/5
D = 5/10 - 36/10
D = 31/10
a = -5/2 ; b = 5/2 ; c = -1
A = 1/(-5/2) + 2/(5/2) + 3/(-1)
A = -2/5 + 2 x 2/5 - 3
A = -2/5 + 4/5 - 15/5
A = -13/5
B = (5/2)/(-5/2) + (-5/2)/(5/2)
B = 5/2 x (-2/5) - 5/2 x 2/5
B = -1 - 1
B = -2
C = (-5/2)/(5/2 + (-1))
C = -5/2 / (5/2 - 2/2)
C = -5/2 / (3/2)
C = -5/2 x 2/3
C = -5/3
D = -5/2 - (-1)/(-5/2 + 5/2)
D = -5/2 + 1 / 0 => impossible le dénominateur ne peut pas être nul
