ex 22,23,24 svpp merci d'avance a ses qui vont reprendre

voila la repose de l'exercice  22  et 23

ex:24=
A=3/5 +1/15. B=25/8 + 2,5/4
=3×3/5×3 + 1/15. =25/8 + 2,5×2/4×2
=9/15 + 1/15 =25+5/8
=9+1/15 =30/8
=10/15 =30÷2/8÷2
=15/4



C=21/9 - 1/3
=21/9 _ 1×3/3×3
=21_