bonjour,
A = 4.8 x 10 ⁻³ + 520 x 10 ⁻⁵
A = 0.0048 + 0.0052 = 0.01 = 10 ⁻²
B = 6 x 10 ² : 15 x 10 ⁶ x 10
B = 6 x 10 ² : 15 x 10 ⁷
B = 0.4 x 10 ⁻⁵ = 4 x 10 ⁻⁶
C = 10 ⁻⁸ x 1 x 10 ⁻¹ sur - 1 ²⁰¹² x 2 ⁻⁶ x 5 ⁻⁶
C = 10 ⁻⁹ : - 1 x 10 ⁻⁶
C = 10 ⁻⁹ : - 10 ⁻⁶
C = - 10 ⁻³