Bonjour,

2/3 de 15 = 2/3 × 15 = (2 × 15) / 3 = 30/3 = 10

4/5 de 35 = 4/5 × 35 = (4 × 35) / 5 = 140/5 = 28

2/3 × 3/2 = 1

(5/7)/(2/3) = 5/7 × 3/2 = 15/14

(7/3)/(14/9) = 7/3 × 9/14 = 63/42 = 3/2

bonjour

2/3 * 15 = 30/3 = 10

4/5 * 35 =  140/5 = 28

2/3 * 3/2 = 6/6 = 1

5/7 : 2 /3 = 5/7 * 3/2 = 15/14

7/3  : 14/9 = 7/3 * 9/14 = 63/42 = 3 /2

je reprends les puissances fausses

10⁵ * 10² * 10 ⁶ = 10 ¹³

10 * 10 ⁻² * 10 ³ = 10 ²

10³ / 10 ⁶ = 10 ⁻³

10⁴ = 10 ⁻² = 10 ⁶

32 * 10 ⁴ = 3.2 * 10⁵

0.056 45 = 5.645 * 10 ⁻²