bonjour
A = 490 x 10² : 21 x 10 ³
A = 490/21 x 10 ⁻¹
A = 70/3 x 10 ⁻¹
B = 105 x 10 ² : 21 x 10 ⁻¹
B = 5 x 10 = 50
C = 60 x 10 ³ : 120 x 10 ⁻³
C = 0.5 x 10 ⁰
C = 5 x 10 ⁻¹
D = 3.6 x 10 ² x 10 ⁻¹² : 0.2 x 10 ⁻⁷
D = 3.6 x 10 ⁻¹⁰ : 0.2 x 10 ⁻⁷
D = 18 x 10 ⁻³ = 0.018 = 1.8 x 10 ⁻²
