Réponse :
Bonjour
Explications étape par étape
Exercice 2
A = -1/3 +2/3 : 4/5
A = -1/3 +2/3 X 5/4
A = -1/3 +10/12
A = -1/3 X 4/4 +10/12
A = -4/12 +10/12 = 6/12 = 1/2
B = 2/3 + 1/2 = 2/3 X 2/2 +1/2 X 3/3 = 4/6 +3/6 = 7/6 = 7/6 X 9/14 = 63/84
17/9 -1/3 17/9 -1/3 X 3/3 17/9 -3/9 14/9
B = 63/84 : 3/3 = 21/28 : 7/7 = 3/4
Ecriture scientifique
81 X 10³ X 6 X 10⁻¹⁰ = 486 X 10³⁻¹⁰ = 27 X 10⁻⁷⁺² = 27 X 10⁻⁵ = 0,00027
18 X 10⁻² 18
