Réponses

2012-10-31T12:31:46+01:00

a:1/3=1/4+1/3X4=1x3/3x4+1/3x4=3/12+1/12=4/12=4x1/4x3=1/3

b:1/4=1/5+1/4X5=1x4/5x4+1/4x5=4/20+1/20=5/20=5x1/5x4=1/4

c:1/5=1/6+1/5X6=1x5/6x5+1/5x6=5/30+1/30=6/30=6x1/6x5=1/5

En conclusion, si a est un entier on obtient : 1/a=1/(a+1)+1/a(a+1)