Réponse :
Bonjour
Explications étape par étape
A = 8 × 10^-9 × 9 × 10^8 / 12 × 10^2
A = [(8×9/12)] × [(10^-9×10^8)/10^2]
A = (72/12) × (10^(-9+8)/10^2)
A = 6 × (10^-1/10^2)
A = 6 × 10^(-1-2)
A = 6.0 × 10^-3
B = -3/13 - 2/3 ÷ 13/15 + 1
B = -3/13 - 2/3 × 15/13 + 1
B = -3/13 -(2×5×3)/(3×13) + 1
B = -3/13 - 10/13 + 1
B = -3/13 - 10/13 + 13/13
B = 0/13
B = 0
