1sur3moins 1sur4 1sur4-1sur5 1sur999-1sur1000 1sur2x3+ +1sur1000
Mathématiques
agossin
Question
1sur3moins 1sur4 1sur4-1sur5 1sur999-1sur1000 1sur2x3+ +1sur1000
1 Réponse
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1. Réponse maudmarine
1/3 - 1/4
= 1 x 4 / 3 x 4 - 1 x 3 / 4 x 3
= 4/12 - 3/12
= 1/12
1/4 - 1/5
= 1 x 5 / 4 x 5 - 1 x 4 / 5 x 4
= 5/20 - 4/20
= 1/20
1/999 - 1/1000
= 1 x 1000 / 999 x 1000 - 1 x 999 / 1000 x 999
= 1000/999000 - 999/999000
= 1/999000
1/2 x 3 + 1/1000
= 3/2 + 1/1000
= 3 x 500 / 2 x 500 + 1/1000
= 1500/1000 + 1/1000
= 1501/1000