bonsoir
5 x 7 x 10 ⁻⁷ = 35 x 10 ⁻⁷ = 3.5 x 10 ⁻⁶
20 * 4 * 10 ⁴ sur 10 ⁻¹² = 80 * 10 ⁴ / 10 ⁻¹² = 80 * 10 ¹⁶ = 8 * 10 ¹⁷
