Réponse :
Explications étape par étape :
Bonjour
A = 8/9 + 4/3 / 6/5
A= 8/9 + 4/3 × 5/6
A= 8/9 + (4×5)/(3×6)
A = 8/9 + (2×2×5) / (3×2×3)
A = 8/9 + 10/9
A= 18/9
A = 2
B = [ ( 1/2 + 1/2) × 2] - 2
B = [ ( 2 /2) × 2] - 2
B = [ 1 × 2] - 2
B = 2 - 2
B = 0
2)
C = 1,5 × 10⁻⁴ × 30 × 10⁵
C = 1,5× 30 × 10⁻⁴⁺⁵
C = 45× 10¹
C = 450
D = ( 4 × 10² × 1,2× ( 10⁻³)⁴) / ( 240 × 10⁻⁷ )
D = ( 4 ×1,2× 10² × ( 10⁻¹²)) / ( 4 × 50 ×1,2 × 10⁻⁷ )
D = ( 10²⁻¹²) / (5× 10¹ × 10⁻⁷)
D = (10⁻¹⁰) / ( 5 × 10⁻⁶)
D = 10⁻¹⁰ ⁻ ⁽⁻⁶⁾ /5
D = 10 ⁻¹⁰⁺⁶ /5
D = 10⁻⁴/5
D = 0,00002
3)
C = 4,5 × 10²
D = 2 × 10⁻⁵
