Réponse :
Explications étape par étape
Bonjour
Exercice 4 :
9/7 x 14/15
= 9/15 x 14/7
= (3 x 3)/(3 x 5) x (2 x 7)/7
= 3/5 x 2
= 6/5
7/8 x 3/14 x 4/9
= 7/14 x 4/8 x 3/9
= 7/(2 x 7) x 4/(2 x 4) x 3/(3 x 3)
= 1/2 x 1/2 x 1/3
= 1/12
17/81 x 9/8 x 7/34 x 64/70
= 17/34 x 9/81 x 64/8 x 7/70
= 17/(2 x 17) x 9/(2 x 9) x (8 x 8)/8 x 7/(7 x 10) = 1/2 x 1/2 x 8 x 1/10
= 8/40
= 8/(5 x 8)
= 1/5
Exercice 5 :
A = 63/40 x 5/42
A = (9 x 7 x 5)/(8 x 5 x 6 x 7)
A = 9/48
B = 3/20 x 80/27
B = (3 x 20 x 4)/(20 x 3 x 9)
B = 4/9
C = 45/64 x 64/81
C = (9 x 5 x 64)/(64 x 9 x 9)
C = 5/9
D = 14/15 x 20/49
D = (2 x 7 x 4 x 5)/(3 x 5 x 7 x 7)
D = 8/21
E = 3/50 x 10/9
E = (3 x 10)/(5 x 10 x 3 x 3)
E = 1/15
F = 20/63 x 81/8
F = (5 x 4 x 9 x 9)/(9 x 7 x 2 x 4)
F = 45/14
G = 27/40 x 32/45
G = (3 x 9 x 8 x 4)/(8 x 5 x 9 x 5)
G = 12/25
H = 27/16 x 56/27
H = (27 x 8 x 7)/(2 x 8 x 27)
H = 7/2
