Réponses

2013-12-31T16:18:01+01:00
A=8/5:21/10
=8/5 x 10/21
=80/105
 
B=5/7+9/2*1/14
=5/7+9/28
=20/28+9/28
=29/28
 
C=5-7*(-2)/5²
=5-7*-2/25
=5+14/25
=125/25+14/25
=139/25