T = (10^-8 ×0,7× 10¹²) ÷ (21×10³)
= [ 10^-8 × 0,7 × 10^(12-3) ] ÷ (21×10³)
= ( 10^-8 × 0,7 × 10⁹) ÷ 21
= ( 10^-8 × 7/10 × 10⁹) ÷ 21
= [10^-8 × (7× 10^-1) ×10⁹] ÷ 21
= ( 10^-8 × 7 × 10⁸) ÷ 21
= (10^-8 × 10⁸) × 7/21
= 10⁰ × 1/3
= 1 × 1/3
par suite:
T = 1/3
U = ( 3×10⁷×3,5) ÷ (21×10³)
= (10⁷÷10³) × [(3×3,5) ÷21]
= (10⁴×3×3,5) ÷ 21
= 3/21 × (10⁴×3,5)
= 1/7 × (10⁴×3,5)
= (10⁴×3,5) ÷ 7
= (10⁴ × 7/2) ÷ 7
= 10⁴/2
= 10000÷2
= 5000
alors:
U = 5000
V = 4/12 × [ [(10^-2)³×10²] ÷ 10^-3 ]
= 1/3 × [ [(10^-6 × 10²] ÷ 10^-3 ]
= 1/3 × [ 10^-4 ÷ 10^-3]
= 1/3 × 10^(-4-(-3))
= 1/3 × 10^-1
= 1/3 × 1/10
= 1/30
d'où :
V = 1/30
