Réponse :
Explications étape par étape
Bonsoir
A = 4/7 + 2/5(1/3 - 4)
A = 4/7 + 2/5(1/3 - 12/3)
A = 4/7 + 2/5 x (-11/3)
A = 4/7 - 22/15
A = 60/105 - 154/105
A = (-94/105)
B = 1/2 x 2/3 x 3/4 x 4/5 x 5/6 x 6/7 x 7/8 x 8/9 x 9/10
B = 1 x 2/2 x 3/3 x 4/4 x 5/5 x 6/6 x 7/7 x 8/8 x 9/9 x 1/10
B = 1/10
C = 7/18 x 2/7 - (5/3 - 1)^2 + 1
C = 7/7 x 2/18 - (5/3 - 3/3)^2 + 1
C = 1/9 - (2/3)^2 + 1
C = 1/9 - 4/9 + 9/9
C = 6/9
C = 2/3
D = 2 / (a + 1) + (1 - 1/a) / (1 + 1/a)
D = 2/(a + 1) + (a/a - 1/a) / (a/a + 1/a)
D = 2/(a + 1) + [(a - 1)/a] / [(a + 1)/a]
D = 2/(a + 1) + (a - 1)/a x a/(a + 1)
D = 2/(a + 1) + (a - 1)/(a + 1)
D = [2 + a - 1]/(a + 1)
D = (a + 1)/(a + 1)
D = 1
