Réponse :
Explications étape par étape
Bonsoir
Exercice 4 :
D = 7/4 - 3/4 x (-1/9)
D = 7/4 + 3/9 x 1/4
D = 7/4 + 1/3 x 1/4
D = 7/4 + 1/12
D = 21/12 + 1/12
D = 22/12
D = (2 x 11)/(2 x 6)
D = 11/6
E = (5 x 10^5 x (2 x 10^(-1))^3) / (24 x 10^2)
E = (5 x 2^3 / 24) x 10^(5-1*3-2)
E = (5 x 8 / 24) x 10^(5-3-2)
E = 5/3 x 10^0
E = 5/3
Exercice 5 :
F = 15 x (10^7)^2 x 3 x 10^(-5)
F = 15 x 3 x 10^(7*2-5)
F = 45 x 10^(14-5)
F = 45 x 10^9
F = 4,5 x 10 x 10^9
F = 4,5 x 10^(1+9)
F = 4,5 x 10^10
G = (7 x 10^(-12) x 6 x 10^5) / (21 x 10^4)
G = (7 x 6 / 21) x 10^(-12+5-4)
G = (7 x 2 x 3)/(3 x 7) x 10^(-12+9)
G = 2 x 10^(-3) => écriture scientifique
G = 0,002 => écriture décimale
