3/7×X=1
3/7X=1
X=1÷3/7
X=1×7/3
X=7/3 (irréductible )
Réponse :La solution est 7/3
Vérifions :
7/3×3/7
=7×3/3×7
=21/21
=21÷7/21÷7
=3/3
=3÷3/3÷3
=1