Bonjour
(2 - 4/5 + 1/3) / (2 + 4/5 + 1/3)
= [ (2 x 15) / (1 x 15) - (4 x 3) / (5 x 3) + (1 x 5) / (3 x 5) ] / [ (2 x 15) / (1 x 15) + (4 x 3) / (5 x 3) + (1 x 5) / (3 x 5) ]
= (30 / 15 - 12 / 15 + 5 / 15) / (30 / 15 + 12 / 15 + 5 / 15)
= [ (30 - 12 + 5) / 15 ] / [ (30 + 12 + 5) / 15 ]
= (23 / 15) / (47 / 15)
= (23 / 15) x (15 / 47)
= (23 x 15) / (15 x 47)
= 23 / 47
Voilà j'espère avoir pu t'aider ^^